Identification_Information: Citation: Citation_Information: Originator: Illinois State Geological Survey Publication_Date: 200304 Title: Illinois Public Land Survey System Edition: 2.2 Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: ISGS GIS Database Issue_Identification: IL_PLSS_Public_Land_Survey_System Publication_Information: Publication_Place: Champaign, Illinois Publisher: Illinois State Geological Survey Online_Linkage: http://www.isgs.illinois.edu/ Online_Linkage: http://illinois.edu Description: Abstract: This data set contains Illinois Public Land Survey System (PLSS) boundaries and designations in line and polygon feature classes. THESE DATA HAVE POSITIONAL INACCURACY OF UP TO 600 FEET IN SOME AREAS OF THE STATE. THEY ARE NOT TO BE USED AT SCALES GREATER THAN 1:62,500. THE DATA ARE NOT APPROPRIATE AS A GEODETIC, LEGAL OR ENGINEERING BASE. The polygon attribute data include meridian, township, range, section and county number (FIPS) designations. The line attributes indicate line type, including the state line, county lines, township and range lines, section lines, Indian treaty boundaries, base lines, principal meridians, and boundaries between areas mapped from different principal meridians. The nominal scale is 1:62,500. As of 2003, the data are typically distributed in geographic coordinates (longitude and latitude), decimal degrees, and the North American Datum (NAD) of 1983, and this is the default spatial reference of the ArcSDE feature dataset in which the data are stored. The data were originally developed, however, in a custom Lambert Conformal Conic projection and were distributed in that coordinate system for several years. The data were digitized in the late 1960s, early 1970s, and in 1984-85 from 7.5- and 15-minute USGS topographic quadrangles. Errors in the location of a given feature are dependent on the accuracy of the original maps and on the accuracy of digitizing. Estimates are that features have an average locational error of approximately plus/minus 100 feet. Some areas of the state have a locational error of approximately 600 feet. In areas of French colonization land grants, where PLSS sections were not actually surveyed, sections and section lines have been added (estimated). A graphic overview of the township and range system in Illinois is included in the file c451.pdf Purpose: These data are appropriate for use as an index and in local and regional thematic analysis. The data are not appropriate as a geodetic, legal or engineering base. The data set was originally created for the purpose of producing maps of well locations in Illinois for geologic research by the ISGS and others. It serves as an important base cartographic element for many types of maps and has been widely distributed and used outside the ISGS. The data set was not and is not intended as a substitute for surveyed locations, such as can be determined by a registered Public Land Surveyor. Although useful in a GIS as a reference base layer for maps, the data set has no legal basis in the definition of boundaries or property lines. Supplemental_Information: Further information in the form of a PDF document and a dBase table is included with the standard distribution file. These resources are identified in the Cross References section. The data were originally known as the ILLIMAP System and were created in the late 1960s and early 1970s for the purpose of producing maps of well locations in Illinois for geologic research by the ISGS and others. It was one of the first efforts in the nation to digitally capture public land survey boundaries. The principal originators of the first version were geologists at the ISGS: Dave Swann, Paul DuMontelle, Dick Mast, and Lindell Van Dyke. The data were initially digitized from 7.5- and 15-minute USGS topographic maps, and this work comprises approximately two-thirds of the present data set. The accuracy was stated as follows: "For the townships digitized from 7.5-minute quadrangles, 95.2 percent of the ILLIMAP distances are within 100 feet of the recorded plat distances, and all are within 180 feet. In townships digitized from 15-minute quadrangles, 82.5 percent of the ILLIMAP distances are within 100 feet of the plat distances, and 98.7 percent are within 200 feet." (ISGS Circular 451, p. 13) Subsequent procedures may have affected the locational accuracy of the data. Please refer to the section entitled Horizontal Positional Accuracy Report. For more information on the origin of the data set, refer to the Process Steps section. Also refer to ISGS Circular 451 (ILLIMAP - A Computer-Based Mapping System for Illinois, Swann, DuMontelle, Mast & Van Dyke, 1970). That publication discusses the original digitizing work, coordinate conversions, methods for the subdivision of regular and irregular sections, and the accuracy of the results. It is included in the standard distribution files under the file name c451.pdf. The database was maintained by the ISGS Computer Services Unit under Van Dyke's direction until 1985 at which time the data were converted to an ArcInfo coverage. The conversion was accomplished by Environmental Systems Research Institute (ESRI) of Redlands, California, working under contract with the ISGS via the Illinois Department of Energy and Natural Resources and its Lands Unsuitable for Mining Program. The remaining one third of the state was digitized from 7.5-minute quadrangles at this time (1984-85.) For more information on the original and updated quadrangles used in the digitizing process, including publication dates, please refer to the Cross References section. Selected small areas have been updated since 1985 as errors were detected. New topographic maps are constantly being published by the USGS. Those data are not routinely incorporated into this data set. In 2003 the data set was transitioned from the ESRI ArcInfo coverage data model to the ESRI ArcSDE enterprise geodatabase data model. The data are stored in an Oracle relational database management system (RDBMS) and maintained using ArcGIS software. At present the data are managed by the Geospatial Analysis and Modeling Section of the ISGS. Recent updates to the data: In March, 1998 the data set as it stood was designated Edition 1.0 for metadata and version management purposes. Edition 1.0 of these data was reviewed for internal logical consistency in March, 1998. As a result, several unneeded .AAT and .PAT items were dropped, tics were replaced, two label errors were corrected and a single polygon was removed. COVER-ID values were recalculated to be unique. See logical consistency report and process steps for March, 1998 for more details. The updated coverage was designated Edition 1.1. Minor corrections to editions 1.1 and 1.2 were made between 1998 and 2002. Refer to the Process Steps section. The most recent updated coverage data set was designated Edition 1.3. In April, 2003 the data set was transitioned to storage in an Oracle RDBMS using the ArcSDE geodatabase model. New line attributes were added to identify base lines, principal meridians, and the boundaries between areas of the state mapped using different base lines and meridians. At that time this metadata document was significantly updated. The result was designated Edition 2.0. In 2006 and 2007, seven polygon code errors were detected and corrected. Refer to the Process Steps section. The most recent updated feature class (this one) was designated Edition 2.2. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: circa 1921 Ending_Date: 1979 Currentness_Reference: Dates of source maps. Status: Progress: Complete Maintenance_and_Update_Frequency: Irregular Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -91.4244 East_Bounding_Coordinate: -87.3840 North_Bounding_Coordinate: 42.4951 South_Bounding_Coordinate: 36.9540 Keywords: Theme: Theme_Keyword_Thesaurus: none Theme_Keyword: public land survey Theme_Keyword: state outline Theme_Keyword: state boundary Theme_Keyword: county boundary Theme_Keyword: township Theme_Keyword: range Theme_Keyword: section Theme_Keyword: illimap Theme_Keyword: base map Theme_Keyword: principal meridian Theme_Keyword: base line Theme_Keyword: indian Theme_Keyword: treaty Place: Place_Keyword_Thesaurus: none Place_Keyword: Illinois Access_Constraints: ISGS information must be obtained directly from the ISGS or from an authorized distributor. Be aware that ISGS information obtained from an unauthorized third party may have been altered subsequent to original distribution, or may no longer be current. Any access to these data, Web sites, computer systems, electronic services, and electronic networks is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section. Use_Constraints: ISGS information is the property of and copyrighted by the Board of Trustees of the University of Illinois with all rights reserved.  University copyright policy is stated in the General Rules Concerning University Organization and Procedure, Article III, Section 4. A link is provided in the Cross References section. Individuals or entities may make fair use of copyrighted ISGS material, such as reproducing a single figure or table, or using a brief text quotation, without obtaining formal permission, but in all cases the Illinois State Geological Survey must be credited as the source of the material. To reproduce ISGS information beyond the fair use standard, permission must be obtained from the ISGS Information Office, 615 East Peabody Drive, Champaign, Illinois 61820, 217-333-4747, isgs@isgs.illinois.edu. License fees and a license agreement may be required, depending on the proposed usage. Any use of these data is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign, the ISGS Terms of Use document available at the ISGS Web site, and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section. Map information is to be used at a scientifically and cartographically appropriate scale, that is, at a scale no greater than indicated on the map or as described in the documentation of the map or map data.  Map information is not appropriate for, and is not to be used as, a geodetic, legal, or engineering base. Map information has no legal basis in the definition of boundaries or property lines and is not intended as a substitute for surveyed locations such as can be determined by a registered Public Land Surveyor. The data do not replace the need for detailed site-specific studies. Point_of_Contact: Contact_Information: Contact_Instructions: Please refer to the Distribution Information section. Native_Data_Set_Environment: ArcSDE 9.1 on Oracle 10g Cross_Reference: Citation_Information: Originator: Illinois State Geological Survey Publication_Date: 1984, 199803 Title: ArcInfo Coverage RE-STATE1 Edition: 1.3 Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: ISGS GIS Database Issue_Identification: re-state1 Publication_Information: Publication_Place: Champaign, Illinois, USA Publisher: Illinois State Geological Survey Other_Citation_Details: This is the progenitor of the ArcSDE PLSS feature dataset from which the distributed data were extracted. Cross_Reference: Citation_Information: Originator: Illinois State Geological Survey Publication_Date: Unpublished Material Title: Index of USGS Quadrangles Digitized for the Illinois PLSS Data Set Geospatial_Data_Presentation_Form: raster digital data Other_Citation_Details: This full-resolution georeferenced TIFF image shows an annotated USGS index of the 15- and 7.5-minute quadrangles used in digitizing the PLSS database, including the updates to the data set that were made in 1984-85. The index has been preserved because it is the only known document that shows the publication dates of the source topographic maps. Note that some of the quadrangles were digitized in the late 1960s and early 1970s, and others in 1984-85. Cross_Reference: Citation_Information: Originator: Illinois State Geological Survey Publication_Date: 20030715 Title: Digitizing History of the ISGS Illinois Public Land Survey System GIS Database Geospatial_Data_Presentation_Form: tabular digital data Series_Information: Series_Name: ISGS GIS Database Issue_Identification: GISDB.IL_PLSS_Digitizing_History_Tb Publication_Information: Publication_Place: Champaign, Illinois Publisher: Illinois State Geological Survey Other_Citation_Details: This dBase table (IL_PLSS_Digitizing_History_Tb.dbf) is included in the standard distribution file. It can be combined with the quadrangle shapefile to show an index of the digitizing history of the PLSS data set. It lists the quadrangle name and ID, map publication date, and the year that quadrangle was digitized, either original digitizing (1970) or updated (1985). Cross_Reference: Citation_Information: Originator: Illinois State Geological Survey Publication_Date: 199210, 199803 Title: Index of US Geological Survey 7.5 Minute Quadrangle Map Series for Illinois Edition: 1.1 Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: ISGS GIS Database Issue_Identification: GISDB.IL_QUAD_24K_Index_Py_Nad83 Publication_Information: Publication_Place: Illinois State Geological Survey Publisher: Champaign, Illinois Other_Citation_Details: This polygon shapefile (IL_QUAD_24K_Index_Py_Nad83.shp) is included with the standard distribution files. A separate metadata document is also included. It can be used in conjunction with IL_PLSS_Digitizing_History_Tb.dbf to create a visual representation of the digitizing history of the state. Cross_Reference: Citation_Information: Title: ISGS Terms of Use Online_Linkage: http://www.isgs.illinois.edu Cross_Reference: Citation_Information: Title: University of Illinois Web Privacy Notice Online_Linkage: http://www.vpaa.uillinois.edu/policies/web_privacy.cfm Cross_Reference: Citation_Information: Title: University Copyright Policy (stated in the General Rules Concerning University Organization and Procedure, Article III, Section 4) Online_Linkage: http://www.uillinois.edu/trustees/rules.cfm#sec34 Cross_Reference: Citation_Information: Title: Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign Online_Linkage: http://www.fs.uiuc.edu/cam/CAM/viii/viii-1.1.html Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: The attributes of the ArcInfo coverage version were reviewed in 1990 using a variety of visual techniques (polygon shading, line shading and line thicknesses tied to attribute values) and GIS processing techniques (checking for logical consistency). Arc attribute values for the items STATELINE, COUNTLINE, TOWNLINE, SECLINE, and INDLINE were verified by generating plots with arcs color-coded by designation. These were visually checked for errors. Polygon attribute values were verified in a similar manner. For example, section numbers were checked by plotting maps with a unique color for each possible section number (1-36). These check-plots were visually inspected for the proper color-quilt pattern in each township, indicating correct item values. Meridian, county, and township designations were verified in the same way. There is no quantitative assessment of attribute accuracy available, however, this coverage has been used extensively by ISGS and DNR personnel since 1984, and it can be assumed most attribute errors have been detected and corrected. There are no know arc or polygon attribute values outside the appropriate value domains. Logical_Consistency_Report: For a description of the logical consistency analysis performed on the original ILLIMAP data in the late 1960s and early 1970s, see the section entitled Accurracy of ILLIMAP on pages 12-15 of ISGS Circular 451. A logical consistency review was performed in March, 1998. At that time the data were maintained in ArcInfo coverage format. The following checks were made: The data set was DESCRIBED and coverage files listed to determine the feature types present. In this data set, the following feature types were found and checked: polygons, arcs, labels, and nodes. The presence of spatial indices was also checked. For PAT and AAT files, each item was checked for the following: domain of allowable values, adherence of values to the domain, definition of attribute items, requirement of all unique values for an item, logic of items redefined over other items, and length of item name as regards conversion to shapefile format. The topology status of the data set was checked, as were LABELERRORS, NODEERRORS (if appropriate), and the PROJECTION definition. The presence of a BND file was verified. The presence and location of TICS were checked. Polygon and chain-node topology were present. There were no dangling arcs. There was one polygon label per polygon, except for the universe polygon. Boundary values were appropriate for the map projection and map units. The fuzzy tolerance was suitable for the nominal scale of 1:62,500. Several unneeded .AAT and .PAT items were dropped, tics were replaced, two label errors were corrected, and a single polygon was removed. COVER-ID values were recalculated to be unique. See the process steps for March, 1998. There are no known attribute values outside the appropriate domains. Completeness_Report: The data set includes section lines, section numbers, known Indian treaty boundaries, township and range lines and numbers, principal meridians, base lines, county lines and the state boundary for all areas of the state. In areas of French colonization land grants, where PLSS sections were not actually surveyed, sections and section lines have been added (estimated) to facilitate the use of the data in the automated determination of locations based on township, range and section values. These areas occur for the most part along the Illinois and Mississippi Rivers. No record remains that would identify the added section lines, short of visual comparison to the topographic maps of any particular area. In 1995, the state boundary along the Ohio River was officially changed, but these changes have not been incorporated. Also, this coverage does not include the portion of the state boundary that extends into Lake Michigan. Rather, the lake shore is depicted as the state boundary. Some data were digitized from USGS 7.5-minute topographic quadrangles, and some from 15-minute quadrangles. As a result, scale varies within the coverage. Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The data were initially digitized in the late 1960s and early 1970s from 7.5- and 15-minute USGS topographic maps, and that work comprises approximately two-thirds of the present data set. The accuracy was stated as follows: "For the townships digitized from 7.5-minute quadrangles, 95.2 percent of the ILLIMAP distances are within 100 feet of the recorded plat distances, and all are within 180 feet. In townships digitized from 15-minute quadrangles, 82.5 percent of the ILLIMAP distances are within 100 feet of the plat distances, and 98.7 percent are within 200 feet." For more information on the original accuracy of the data set, see ISGS Circular 451 (ILLIMAP - A Computer-Based Mapping System for Illinois, Swann, DuMontelle, Mast & Van Dyke, 1970). That document is provided with the standard distribution files as c451.pdf. In 1985 the data were converted to an Arc/Info coverage. The conversion was accomplished by Environmental Systems Research Institute (ESRI) of Redlands, California, working under contract with the ISGS via the Illinois Department of Energy and Natural Resources and its Lands Unsuitable for Mining Program. The remaining one third of the present data set was digitized from 7.5-minute quadrangles at this time (1984-85.) Details of the digitizing process are unavailable. It is reasonable to assume the positional accuracy was improved for newly digitized areas. However, it is also likely there was some degradation to the positional accuracy of the previously existing data due to automated coverage processing, for example, the use of the ArcEdit CLEAN command. Subsequently, the horizontal positional accuracy was spot verified by manual overlay of source and hard-copy plots. Arcs within one line-width of source maps were deemed acceptable. The size of the sample set is unknown. Errors in the location of a given feature are dependent on the accuracy of the original maps and on the accuracy of digitizing and processing. Current estimates are that features in the data set have an average locational error of approximately plus/minus 100 feet. The greatest known locational errors are on the order of 600 feet. The source maps are subject to USGS mapping accuracy standards. For more information on the source maps used, refer to the Cross References and Process Steps sections. Lineage: Source_Information: Source_Citation: Citation_Information: Originator: United States Geological Survey Publication_Date: varies from circa 1921 to 1979 Title: USGS 7.5- and 15-minute topographic quadrangles Geospatial_Data_Presentation_Form: map Series_Information: Series_Name: Topographic quadrangles Issue_Identification: various Source_Scale_Denominator: 24000 and 62500 Type_of_Source_Media: paper Source_Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: circa 1921 Ending_Date: 1979 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: none Source_Contribution: Lines depicting state, county, township, range and section boundaries, and Indian treaty lines in the state of Illinois. Source_Information: Source_Citation: Citation_Information: Originator: Illinois State Geological Survey Publication_Date: 199803 Title: Index of US Geological Survey 30 x 60 Minute Quadrangle Map Series for Illinois Geospatial_Data_Presentation_Form: vector digital data Series_Information: Series_Name: ISGS GIS database Issue_Identification: quad100 Publication_Information: Publication_Place: Champaign, Illinois Publisher: Illinois State Geological Survey Type_of_Source_Media: GIS data set Source_Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 199803 Source_Currentness_Reference: publication date Source_Citation_Abbreviation: none Source_Contribution: tics Process_Step: Process_Description: The data were originally known as the ILLIMAP System and were created in the late 1960s and early 1970s for the purpose of producing maps of well locations in Illinois for geologic research by the ISGS and others. It was one of the first efforts in the nation to digitally capture public land survey boundaries. The principal originators of the first version were geologists at the ISGS: Dave Swann, Paul DuMontelle, Dick Mast, and Lindell Van Dyke. The data were initially digitized from 7.5- and 15-minute USGS topographic maps, and this work comprises approximately two-thirds of the present data set. A list of these quadrangles is included with the standard distribution file as IL_PLSS_Digitizing_History_Tb.dbf. For more information on the origin of the data set, see ISGS Circular 451 (ILLIMAP - A Computer-Based Mapping System for Illinois, Swann, DuMontelle, Mast & Van Dyke, 1970). That publication discusses the original digitizing work, coordinate conversions, methods for the subdivision of regular and irregular sections, and the accuracy of the results. Process_Date: 1970 Process_Contact: Contact_Information: Contact_Person_Primary: Process_Step: Process_Description: The database was maintained by the ISGS Computer Services Unit under Van Dyke's direction until 1985 at which time the data were converted to an Arc/Info coverage. The conversion was accomplished by Environmental Systems Research Institute (ESRI) of Redlands, California, working under contract with the ISGS via the Illinois Department of Energy and Natural Resources and its Lands Unsuitable for Mining Program. The remaining one third of the state was digitized from 7.5-minute quadrangles at this time (1984-85.) A list of these quadrangles is included in the standard distribution file as IL_PLSS_Digitizing_History_Tb.dbf. No specifics on the automation process are available. It is assumed the automation process was typical of that for ArcInfo data sets of the time, implying digitization from source maps, editing and error checking with Arc, ArcEdit and ArcPlot, building topology, and subsequent revision and update. Process_Date: 1984-85 Process_Contact: Contact_Information: Contact_Person_Primary: Process_Step: Process_Description: Selected small areas have been updated since 1985 as errors were detected. The updates were typically minor corrections to polygon or line attributes. A few line segments have been re-digitized over time. Paper records exist for some updates. Updates to the data were not recorded in formal electronic metadata form until March of 1998. New topographic maps are constantly being published by the USGS. Those data were not routinely incorporated into this data set. Process_Date: 1985-1998 Process_Contact: Contact_Information: Contact_Person_Primary: Process_Step: Process_Description: An internal logical consistency check was performed in March, 1998. Refer to the Logical Consistency report. As a result, the following changes/updates were made to the data: TICS - The data set had eight tics along the northern border of the state. For better tic distribution, these were replaced with ten tics from USGS 30-minute by 60-minute quadrangle corners, evenly distributed around the state. However, users needing registration tics for use with these data (or a subset of these data) should expect to create a task-specific tic set, usually based on section corners. REMOVAL OF ITEMS - The following empty .AAT items were dropped: STATE2C.OLD#, STATE2C.OLD-ID, ORIG-ID, SYMBOL. UNIQUE COVER-ID VALUES - COVER-ID values in the .AAT and .PAT were calculated to equal (COVER# - 1) in order to make them unique. NODEERRORS - These NODEERRORS were corrected: > Polygon 57706 has 2 label points. > Label User ID: 58883 > Label User ID: 28627 > Polygon 57806 has 2 label points. > Label User ID: 29333 > Label User ID: 29374 EXTRA POLYGON - An extra polygon was removed. RE-STATE1# = 57700 in .PAT had TWP = '4 2N 2E'. This polygon should actually be a part of the polygon to the immediate west (RE-STATE1# = 57698, TRS = '4 2N 1E25'). The hardcopy version of the USGS Astoria quad is suspected to be in error - the markings are ambiguous. Meridian, township, range and section designation were verified using 1997 and 1998 plat map books for Mason and Schuyler Counties. The arc that separates the two polygons (re-state# = 123731) was removed. (The ID numbers in this paragraph refer to edition 1.0 of the coverage.) At this time it was decided to maintain a record of GIS versions of this data set. The data set prior to review was (arbitrarily) designated Edition 1.0. Upon completion of the review, the data set was designated as Edition 1.1. Process_Date: 199803 Process_Contact: Contact_Information: Contact_Person_Primary: Process_Step: Process_Description: Polygon attribute value COUNTY-NUMBER was updated for 2 polygons. The updated data set was designated Edition 1.2. Process_Date: 19990624 Process_Contact: Contact_Information: Contact_Person_Primary: Process_Step: Process_Description: Two errors were discovered in polygon attribute values. The errors were corrected and are listed below (both in Jersey County.) Corrected values were taken from a USGS DRG of the Nutwood quadrangle. Was 3, 7N, 13W, 30 Corrected to 3, 7N, 13W, 29 Was 4, 12S, 1W, 6 Corrected to 3, 7N, 13W, 19 (The values are MERIDIAN, TOWNSHIP, RANGE, SECTION) The updated data set was designated Edition 1.3 Process_Date: 20020919 Process_Contact: Contact_Information: Contact_Person_Primary: Time_of_Day: 10564500 Process_Step: Process_Description: The coverage (currently at edition 1.3) was imported into an ArcSDE enterprise geodatabase feature dataset for storage. The resulting SDE edition is designated Edition 2.0. The jump from edition 1.3 to 2.0 reflects the significant change in fundamental data storage model from coverage to ArcSDE enterprise geodatabase. It also reflects the change in default spatial reference from the customary ISGS Lambert Conformal Conic projection (NAD27) to a geographic coordinate system (longitude, latitude) in decimal degrees (NAD83). The SDE name of the data set is IL_PLSS_Public_Land_Survey_System. The various coverage feature classes were imported using ArcCatalog 8.2. The label point feature classes for township and section polygons were not imported. Prior to import, the spatial reference of the data set was changed to Geographic, decimal degrees, NAD83 in double precision. The previous spatial reference was the customary ISGS Lambert Conformal Conic projection. After import, several informal tests were done to verify that the data were not modified during import. Also after import, the SDE geodatabase was exported to a personal geodatabase. The IL_PLSS_Section_Ln feature class was edited to add three new fields: BASELINE, MERIDIAN, and MERIDBND. These were edited respectively to identify township, range, and section lines that comprise base lines, principal meridians, and the boundaries between areas mapped from different base lines and meridians. The edited feature classes were successfully re-imported into the SDE geodatabase. This process was performed for three reasons: (1) to add the new attribute data, (2) to test the ability to extract a layer from an SDE feature dataset, edit it, and successfully re-integrate it, and (3) to verify that there was no drift in the XY coordinate values of line vertices in the export and import operation. Also at this time, this metadata file was considerably rewritten and updated. Of special note are the additional PDF and dBase files that provide a great deal of legacy information about this data set. These are listed in the Cross References section. Process_Date: 200304 Process_Contact: Contact_Information: Contact_Person_Primary: Process_Step: Process_Description: The data were exported from enterprise SDE database to coverage and shapefile formats for distribution. Note that upon export from an enterprise SDE database to the coverage format using ArcGIS 8.2, a generic set of tics is created for the coverage. It is assumed they are related in some way to the maximum and minimum extent coordinates for the coverage, however, one of the tics is placed far outside the coverage extent. Therefore, these tics should be ignored. Process_Date: 20030415 Process_Step: Process_Description: Coding errors in the section polygon feature class were discovered. Six polygons had miscoded section number values. The errors were verified by ISGS staff by comparison with 24K DRGs and then corrected. The corrected errors are: CALHOUN T08SR02W27 - miscoded 26 - corrected to 27 CALHOUN T08SR02W34 - miscoded 35 - corrected to 34 GREENE T11NR14W24 - miscoded 23 - corrected to 24 PIKE T04SR02W33 - miscoded 34 - corrected to 33 TAZEWELL T23NR07W09 - miscoded 08 - corrected to 09 WOODFORD T27NR04W35 - miscoded 34 - corrected to 35 The updated feature class is designated edition 2.1. Process_Date: 20060807 Process_Step: Process_Description: A coding error in the section polygon feature class was discovered. A polygon had miscoded section number value. The error was verified by ISGS staff by comparison with 24K DRGs and then corrected. The corrected error is: WOODFORD T27NR04W34 - miscoded 33 - corrected to 34 The updated feature class is designated edition 2.2. Process_Date: 20070314 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: String Point_and_Vector_Object_Count: 125956 SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: G-polygon Point_and_Vector_Object_Count: 57926 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Geographic: Latitude_Resolution: 0.000001 Longitude_Resolution: 0.000001 Geographic_Coordinate_Units: Decimal degrees Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Vertical_Coordinate_System_Definition: Altitude_System_Definition: Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: IL_PLSS_Section_Ln Attribute: Attribute_Label: STATELINE Attribute_Definition: Boolean - Indicates if the line is a part of the state boundary Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: false Enumerated_Domain: Enumerated_Domain_Value: 1 Enumerated_Domain_Value_Definition: true Attribute: Attribute_Label: COUNTLINE Attribute_Definition: Boolean - Indicates if the line is a part of a county boundary Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: false Enumerated_Domain: Enumerated_Domain_Value: 1 Enumerated_Domain_Value_Definition: true Attribute: Attribute_Label: SECLINE Attribute_Definition: Boolean - Indicates if the line is a part of a section boundary Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: false Enumerated_Domain: Enumerated_Domain_Value: 1 Enumerated_Domain_Value_Definition: true Attribute: Attribute_Label: INDLINE Attribute_Definition: Boolean - Indicates if the line is a part of an Indian treaty boundary Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: false Enumerated_Domain: Enumerated_Domain_Value: 1 Enumerated_Domain_Value_Definition: true Attribute: Attribute_Label: TOWNLINE Attribute_Definition: Boolean - Indicates if the line is a part of a township and range boundary Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: false Enumerated_Domain: Enumerated_Domain_Value: 1 Enumerated_Domain_Value_Definition: true Attribute: Attribute_Label: BASELINE Attribute_Definition: Indicates if a line is part of a base line, and if so, which base line Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: not part of a base line Enumerated_Domain: Enumerated_Domain_Value: 2 Enumerated_Domain_Value_Definition: part of the 1805 base line in southern Indiana associated with the 2nd principal meridian Enumerated_Domain: Enumerated_Domain_Value: 3 Enumerated_Domain_Value_Definition: part of the 1805 base line in southern Illinois associated with the 3rd principal meridian Enumerated_Domain: Enumerated_Domain_Value: 4 Enumerated_Domain_Value_Definition: part of the 1815 base line in western Illinois associated with the 4th principal meridian Attribute: Attribute_Label: MERIDIAN Attribute_Definition: Indicates if the line is a part of a principal meridian, and if so, which meridian Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: not part of a principal meridian Enumerated_Domain: Enumerated_Domain_Value: 2 Enumerated_Domain_Value_Definition: part of the 2nd principal meridian Enumerated_Domain: Enumerated_Domain_Value: 3 Enumerated_Domain_Value_Definition: part of the 3rd principal meridian Enumerated_Domain: Enumerated_Domain_Value: 4 Enumerated_Domain_Value_Definition: part of the 4th principal meridian Attribute: Attribute_Label: MERIDBND Attribute_Definition: Indicates if the line is a part of the boundary between areas mapped from different principal meridians and base lines, and if so, which ones Attribute_Definition_Source: ISGS Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 0 Enumerated_Domain_Value_Definition: not a boundary between areas mapped from different meridians and base lines Enumerated_Domain: Enumerated_Domain_Value: 23 Enumerated_Domain_Value_Definition: boundary between areas mapped from the 2nd and 3rd principal meridians Enumerated_Domain: Enumerated_Domain_Value: 34 Enumerated_Domain_Value_Definition: boundary between areas mapped from the 3rd and 4th principal meridians Detailed_Description: Entity_Type: Entity_Type_Label: IL_PLSS_Section_Py Attribute: Attribute_Label: MERIDIAN Attribute_Definition: The value of the principal meridian from which the section was mapped Attribute_Definition_Source: Generally accepted nomenclature Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 2 Enumerated_Domain_Value_Definition: Mapped from the 2nd Principal Meridian and 1805 base line in southern Indiana Enumerated_Domain_Value_Definition_Source: ISGS Circular 451, figure 1 Enumerated_Domain: Enumerated_Domain_Value: 3 Enumerated_Domain_Value_Definition: Mapped from the 3rd Principal Meridian and 1805 base line in southern Illinois Enumerated_Domain_Value_Definition_Source: ISGS Circular 451, figure 1 Enumerated_Domain: Enumerated_Domain_Value: 4 Enumerated_Domain_Value_Definition: Mapped from the 4th Principal Meridian and 1815 base line in western Illinois Enumerated_Domain_Value_Definition_Source: ISGS Circular 451, figure 1 Attribute: Attribute_Label: SECTION Attribute_Definition: The integer section number Attribute_Definition_Source: Generally accepted nomenclature Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 36 Attribute: Attribute_Label: COUNTY_NUMBER Attribute_Definition: The Federal Information Processing Standards (FIPS) value for counties in Illinois. Odd integers only. Attribute_Definition_Source: The Federal Information Processing Standards Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 203 Attribute: Attribute_Label: TWPNUM Attribute_Definition: The integer township identifier Attribute_Definition_Source: Generally accepted nomenclature Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 46 Attribute: Attribute_Label: RNGNUM Attribute_Definition: The integer range identifier Attribute_Definition_Source: Generally accepted nomenclature Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: 1 Range_Domain_Maximum: 14 Attribute: Attribute_Label: RNGDIR Attribute_Definition: Indicates whether the range is east or west of the principal meridian Attribute_Definition_Source: Generally accepted nomenclature Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: E Enumerated_Domain_Value_Definition: east Enumerated_Domain: Enumerated_Domain_Value: W Enumerated_Domain_Value_Definition: west Attribute: Attribute_Label: TWPDIR Attribute_Definition: Indicates whether the township is north or south of the base line Attribute_Definition_Source: Generally accepted nomenclature Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: N Enumerated_Domain_Value_Definition: north Enumerated_Domain: Enumerated_Domain_Value: S Enumerated_Domain_Value_Definition: south Overview_Description: Entity_and_Attribute_Overview: The data set includes line attributes that identify the following boundaries: state, county, township and range, section, and areas mapped from different meridians. Principal meridians and base lines are also identified. Polygon attributes identify the meridian, township, range, section, and county number for sections. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Information Office, Illinois State Geological Survey (ISGS), a division of the Institute of Natural Resource Sustainability (INRS) of the University of Illinois Contact_Address: Address_Type: mailing and physical address Address: 615 East Peabody Drive City: Champaign State_or_Province: Illinois Postal_Code: 61820 Country: USA Contact_Voice_Telephone: 217-333-4747 Contact_TDD/TTY_Telephone: 217-785-0211 Contact_Electronic_Mail_Address: isgs@isgs.illinois.edu Hours_of_Service: 8:00 a.m. - 4:30 p.m., Monday-Friday, U.S. Central Time Distribution_Liability: Refer to the Legal Notices of Terms and Conditions of the University of Illinois Web Privacy Policy (there is a link in the Cross References section) for policy statements regarding the following: Disclaimer of Liability Disclaimer of Warranties and Accuracy of Data Disclaimer of Endorsement Disclaimer for External Links Disclaimer of Duty to Continue Provision of Data Security Choice of Law By obtaining these data you agree to the provisions of the University of Illinois Web Privacy Policy, regardless of the manner in which the information was obtained. Technical_Prerequisites: The data are intended for use with GIS software. The ISGS uses ESRI ArcGIS software, however, ESRI formats can be imported into many different GIS software packages. It is expected that customers who obtain these data have the technical expertise to use GIS software. The ISGS does not provide software support of any kind. Metadata_Reference_Information: Metadata_Date: 20090224 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Instructions: Please refer to the Distribution Information section. Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time Metadata_Access_Constraints: The access constraints as stated for the data apply also to the metadata. Refer to the Access Constraints section of the Identification Information section. Metadata_Use_Constraints: The use constraints as stated for the data apply also to the metadata. Refer to the Use Constraints section of the Identification Information section. Metadata_Extensions: Online_Linkage: http://www.esri.com/metadata/esriprof80.html Profile_Name: ESRI Metadata Profile