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Polygons outlining combined leased areas and mined-out areas, Yampa coal field

Frequently-anticipated questions:

• What does this data set describe?
  1. How should this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• How was the data set created?
  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
  3. What similar or related data should the user be aware of?
• How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How should this data set be cited?

   U.S. Geological Survey, Central Energy Resources Team, Johnson, E.A., Roberts, L.N.R., and Brownfield, M.E., 2000, Polygons outlining combined leased areas and mined-out areas, Yampa coal field: U.S. Geological Survey, Denver, CO USA.

   Online Links:

   • <http://energy.cr.usgs.gov/coal/nca/cpgis.htm>

   Other_Citation_Details:

   In subdir 100k (defines appropriate maximum scale for data use)
   chap. P, Geology and resource assessment of the middle and upper coal groups in the Yampa coal field, northwestern Colorado

   This is part of the following larger work.

   Kirschbaum, M.A., Roberts, L.N.R., and Biewick, L.R.H., 2000, Geologic Assessment of Coal in the Colorado Plateau: U.S. Geological Survey Professional Paper 1625-B, U.S. Geological Survey, Denver, CO.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -107.6527

   East_Bounding_Coordinate: -106.9495

   North_Bounding_Coordinate: 40.4962

   South_Bounding_Coordinate: 40.2936

3. What does it look like?

4. Does the data set describe conditions during a particular time period?

   Calendar_Date: 2000

   Currentness_Reference: Publication Date

5. What is the general form of this data set?

   Geospatial_Data_Presentation_Form: map

6. How does the data set represent geographic features?
   1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • GT-polygon composed of chains (23)

   2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest .0001. Longitudes are given to the nearest .0001. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.4.
      The flattening of the ellipsoid used is 1/294.98.
      

7. How does the data set describe geographic features?

   yamaleas.dbf

   Shapefile Attribute Table (Source: None)

   Area

   Area of polygon (Source: Software computed)

   Range of values
   Minimum:	0.000
   Maximum:	0.003

   Perimeter

   Perimeter of polygon (Source: Software computed)

   Range of values
   Minimum:	0.016
   Maximum:	0.528

   Leas_mine

   Lease number

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • U.S. Geological Survey, Central Energy Resources Team
   • Johnson, E.A.
   • Roberts, L.N.R.
   • Brownfield, M.E.

2. Who also contributed to the data set?

3. To whom should users address questions about the data?
   U.S. Geological Survey, Central Energy
   c/o Johnson, E. A.
   PO Box 25046 MS 939 Denver Federal Center
   Denver, CO 80225
   USA
   

   303.236.4857 (voice)
   

Why was the data set created?

The Nation's coal resources are being assessed by the USGS. This assessment identifies and characterizes the coal beds and coal zones that will provide the bulk of the nation's coal-derived energy during the next century. This assessment is different from previous large-scale USGS assessments because files and databases are being stored in a digital format and are being analyzed using a Geographic Information System (GIS).

How was the data set created?

1. From what previous works were the data drawn?

2. How were the data generated, processed, and modified?

   Date: 1998 (process 1 of 1)

   These shapefiles consist of polygons that are merged State and Federal leases from one source and mined-out areas from another source. Yama_leas is for the A coal zone, yamb_leas is for the B coal zone, etc. A coal lease area polygon coverage for the Yampa Coalfield was created using three Bureau of Land Management (BLM) 100k maps (Craig, 1979; Steamboat Springs, 1982; and Meeker, 1979) provided by the Craig District Office. Each map was scanned and then REGISTERed and RECTIFYed in ARC/INFO. Coverages were created y digitizing lease boundary lines that were hand-drawn by BLM officials. Three coverages were created from the maps and then MAPJOINed. Officials at the BLM and E.A. Johnson were able to determine which leases involved which coal zones, so the boundaries could be used to exclude resources for the particular coal zone. In regard to the coal leases, if the company had a specific bed under lease then the entire zone containing the bed was eliminated. In those cases where the company had all of the coal under lease, all four zones were eliminated.
   From the original coverage with all the lease boundaries in the Yampa area, the pertinent lease polygons for each coal zone were extracted to create four separate coverages, one for each coal zone. The lease lines where offset from the lines in the Township and Range coverage that was used for the coal assessment in the Yampa coal field (see metadata file, yam_tr.met) and were also offset from lines in the coverage for surface and coal ownership (see metadata file, yam_fin.met). Consequently, we snapped the lease coverage, first to the yam_tr coverage using a snapping distance of 70 to create and new coverage and the arcs in the new coverage were then snapped to the arcs in the ownership coverage.
   Active and inactive mine polygons were derived from three different sources. Paper maps were digitized using ARC/INFO by the USGS. Mylars were scanned and converted to ARC/INFO coverages by contractor or the Colorado Geological Survey. Digital files from these three sources were merged into one cohesive shapefile and those mines needed for coverage of the Yampa coal field were selected and converted to a separate shapefile. Details on the coverage for active and inactive coal mines in the Yampa coal field can be found in the metadata file yam_mine.met. Only the A and D coal zones have been actively mined, so this coverage does not affect the C and B coal zones. The coverage for the lease areas was unioned with the coverage for the mine areas. In Arcedit, 1 or rpoly# = 1 were selected and 'put' into a new coverage. The result is a coverage with the lease areas, mined areas, and the outer-most lines of on area if a mine area overlapped with a lease area.

3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

1. How well have the observations been checked?

2. How accurate are the geographic locations?

3. How accurate are the heights or depths?

4. Where are the gaps in the data? What is missing?

   Complete.

5. How consistent are the relationships among the observations, including topology?

   Polygon topology present.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None

Use_Constraints: Appropriate maximum scale for data use is 100k.

1. Who distributes the data set? (Distributor 1 of 1)
   U.S. Geological Survey, Central Energy
   PO Box 25046 MS 939 Denver Federal Center
   Denver, CO 80225
   USA
   

   303.236.4608 (voice)
   

2. What's the catalog number I need to order this data set?

   Shapefile

3. What legal disclaimers am I supposed to read?

   Any use of trade, product, or company names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although these data have been processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made by the USGS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. Comparison with other data sets on lease areas and mine areas for the same area from other time periods might be inaccurate due to inconsistencies resulting from changes in lease and mine boundaries and in mapping convention over time. This data is not a legal document and is not intended to be used as such.

4. How can I download or order the data?
   • Availability in digital form:

     Data format:	ARC/INFO coverage, export file and shapefile (version ARC/INFO 7.0.4, ArcView 2.1)
     Network links:	<http://energy.cr.usgs.gov/coal/nca/cpgis.htm>
     Media you can order:	CD-ROM (format ISO 9660)

   • Cost to order the data: none

5. What hardware or software do I need in order to use the data set?

   need ARC/INFO 7.0.4 or greater and/or ArcView 2.1 or greater and/or ArcExplorer (which can be downloaded free from <URL:http://www.esri.com>) and/or other software that can read ARC/INFO coverages, ARC/INFO export files, and/or shapefiles
   

Who wrote the metadata?

Dates:

Last modified: 03-Feb-1999

Metadata author:

U.S. Geological Survey, Central Energy
PO Box 25046 MS 939 Denver Federal Center
Denver, CO 80225
USA

303.236.4608 (voice)

Metadata standard:

Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)