The Public Land Surveys data set was generated for the Front Range Infrastructure Resources (FRIR) Project as a base cartographic layer. The data set contains the project's 45 1:24,000-scale quadrangle demonstration area that covers the Front Range of Colorado, south from Ft. Collins to the southern portion of Denver metropolitan area (not including Highlands Ranch, Douglas County); and west from Denver International Airport to the eastern foothills of the Rocky Mountains. For more information on this project, visit the Colorado Front Range Infrastructure Resources Project web site: (URL:http://rockyweb.cr.usgs.gov/frontrange/datasets.htm) Procedures involved in compiling the PLSS data include (1) Obtaining the Digital Line Graph (DLG) vector data by 1:24,000-scale USGS quadrangle tiles, (2) merging the 1:24,000-scale quadrangle tiles into one seamless data set, and (3) translating and reattributing the features into user-friendly data sets. The translated attribution is described below in the Supplemental_Information section.
The demand for GIS data has increased recently, especially in rapidly growing metropolitan areas. Many state, regional, and local planning agencies require up-to-date boundaries and other cartographic base information for various applications including modeling urban growth, determining land suitability for future development, monitoring land use changes and impacts on the environment, understanding land use patterns, and developing policies that could encourage or discourage certain land use zoning. Base cartographic layers are part of the USGS FRIR project cooperative effort to provide qualitative and quantitative information about infrastructure (aggregate, energy, water, habitat) features needed by growing urban regions like the Denver metropolitan area. The objective of the project is to develop GIS information about boundaries and other themes in such a way that decision makers can use this information to make land use planning decisions, growth models and will be used by the project scientists for multiple studies of the changing landscape of the Front Range and the impact on various resources. In addition to PLSS, the USGS has created six other base cartographic layers consisting of: roads (FRIRD), miscellaneous transportation (FRIMT), railroads (FRIRR), manmade structures (FRIMS), boundaries (FRIBD), and hydrography (FRIHY). The PLSS coverage FRIPL contains line and polygon attributed features. The data layers are available at http://rockyweb.cr.usgs.gov/frontrange/datasets.htm
CODES: PLSS OVERLAY This document lists the codes specific to the coverage as they pertain to item fields. The original classification system is taken from DLG major/minor attribute codes. The CAT item specifies the overlay type and takes the place of DLG major codes. See http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html for the complete document of DLG attributes. Field Definitions: CAT Theme Category PIC Primary Identification Code DSC Descriptive Code TWN Township Value (6 places - TTTNNN) TTT = (200 = North, 300 = South) NNN = Number of the Township (036) RNG Range Value (6 places - RRRNNN) RRR = (400 = East, 500 = West) NNN = Number of Range (037) SLG PLSS Section Number/Land Grant Identifier ORG Origin of Survey (From USGS Standards for DLGs) LABEL Feature Definition TWNRNG Redefined TWN and RNG MATT Redefined PIC and DSC Codes into one field SAMPLE .PAT INFO FILE: CAT =30 PLSS Category PIC =110 PLSS area DSC =999 no descriptive code TWN =300002 township value RNG =500069 range value SLG = 15 section 15 ORG = 6 origin of survey value (From USGS Standards for DLGs) LABEL = PLSS Section ** REDEFINED ITEMS ** TWNRNG =300002500069 Redefined Items TWN and RNG MATT =110999 Redefined Items PIC and DSC -------------------- !! ATTENTION !! NEATLINE: designated by PIC and DSC codes of 777 NULL VALUES: '9's are used to fill blank fields -------------------- ** PIC codes for LINE features: PIC Definition 700 township/range line 701 section line ** PIC codes for POLYGON attributes: PIC Definition 110 PLSS area 114 Unsurveyed Area ** PIC codes for NODES: none ** DSC codes: DSC Definition 201 approximate position (within 200 feet)
The Public Land Survey System (PLSS) data in this coverage originated from 7.5-minute USGS Digital Line Graph PLSS files in North American Datum 1927. These files were paneled together into a single coverage and the coverage was re-projected to North American Datum 1983. No attempt was made in the coverage to clip overshoot data or extend undershoot data resulting from the datum shift.
The data is revised from the original DLG vector data that was collected at 1:24000-scale within the 40 foot map accuracy standards. See DLG standards at (http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html) The data was collected for government use and represents the results of data collection for a specific activity. USGS makes no representation as to the suitability or accuracy of the data for any other purpose and disclaims any liability for errors that the data may contain. As such, it is only valid for its intended use, content, time, and accuracy specifications. While there are no explicit constraints on the use of the data, please exercise appropriate and professional judgment in the use and interpretation of this data. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from this data.
U.S. Geological Survey, Rocky Mountain Mapping Center, Denver Federal Center Bldg 810, P.O. Box 25046, MS 516
The final editing and structuring of these data sets were completed by the FRIR project members at the Rocky Mountain Mapping Center.
The attribution for the PLSS data was verified for consistency throughout the demo project area. Check plots were used to compare attribution and spatial extent. See Part 3, Attribute Coding of Standards for Digital Line Graphs at (http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html)
Polygon and chain-node topology present. All areas are closed polygons containing one attributed label point. Arcs have an attribute code if appropriate.
The Land Survey System (PLSS) and other special surveys within, and exclusions within, and exclusions from, public domain lands are shown on USGS quadrangle maps. Survey corners, lines, and areas within the public domain States are mapped and collected as DLG-3 data. The data was converted to the FRIPL data set. The attributed lines, and polygons reflect the translated attribution described in the Supplemental_Information section. Nodes (PLSS section corner or PLSS closing corner) are unattributed. See capture conditions in Part 2-:Standards for Digital Line Graphs and at (URL:http://rockyweb.cr.usgs.gov/nmpstds/dlgstds.html)
The PLSS vector data is within 40 ft. to the ground planimetry. The original data is from a mosaic of 1:24000-scale DLGs derived from stable-base 1:24000-scale USGS topographic maps. See National Map Accuracy Standards at (URL:http://mapping.usgs.gov/standards/).
USGS PLSS DLG vector data.
45 PLSS DLG's were combined to create FRIPL
FRIPL items are used to describe the physical and cultural characteristics of line, and polygon elements. Attribute codes are used to reduce redundant information, provide enough reference information to support integration with larger data bases, and describe the relationships between cartographic elements. FRIPL.PAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 AREA 8 18 F 5 9 PERIMETER 8 18 F 5 17 FRIPL# 4 5 B - 21 FRIPL-ID 4 5 B - 25 CAT 2 2 I - 27 PIC 3 3 I - 30 DSC 3 3 I - 33 TWN 6 6 I - 39 RNG 6 6 I - 45 SLG 6 6 I - 51 ORG 2 2 I - 53 LABEL 50 50 C - ** REDEFINED ITEMS ** 33 TWNRNG 12 12 I - 27 MATT 6 6 I - FRIPL.AAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 FNODE# 4 5 B - 5 TNODE# 4 5 B - 9 LPOLY# 4 5 B - 13 RPOLY# 4 5 B - 17 LENGTH 8 18 F 5 25 FRIPL# 4 5 B - 29 FRIPL-ID 4 5 B - 33 CAT 2 2 I - 35 PIC 3 3 I - 38 DSC 3 3 I - 41 LABEL 50 50 C - ** REDEFINED ITEMS ** 35 MATT 6 6 I - FRIPL.NAT: COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME 1 ARC# 4 5 B - 5 FRIPL# 4 5 B - 9 FRIPL-ID 4 5 B -
Field Definitions: CAT Theme Category (DLG PLSS = 300) PIC Primary Identification Code DSC Descriptive Code TWN Township Value (6 places - TTTNNN)) TTT = (200 = North, 300 = South) NNN = Number of the Township (036) RNG Range Value (6 places - RRRNNN) RRR = (400 = East, 500 = West) NNN = Number of Range (037) SLG PLSS Section Number/Land Grant Identifier ORG Origin of Survey (From USGS Standards for DLGs) LABEL Feature Definition TWNRNG Redefined TWN and RNG MATT Redefined PIC and DSC Codes into one field
Rocky Mountain Mapping Center Denver Federal Center Bldg 810 P.O. Box 25056, MS 516
Contact via email (FAX 303-202-4313)
Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.
Front Range infrastructure resources public land survey system geographic features
Front Range infrastructure resources public land survey system geographic features
ArcIMS Image Map Service
A web-based interactive mapping system that accesses an ArcIMS Map Service running on certmapper.cr.usgs.gov.
Rocky Mountain Mapping Center Denver Federal Center Bldg 810 P.O. Box 25056, MS 516