3. How do I find the GPS coordinates for the corner of a specific Section/Township/Range in Colorado?
You can get latitude/longitude by hovering your mouse over the area and looking at lat/long in your bottom status bar.
4. Where can I get the elevation for a specific latitude/longitude point?
“USGS –The National Map” has an Elevation Query Web Service that will return the elevation in feet or meters for a specific latitude/longitude point from the USGS Seamless Elevation data sets, hosted at the EROS Data Center. The website is:
http://gisdata.usgs.net/XMLWebServices/TNM_Elevation_Service.asp
5. Where are the coordinate data located?
If LSIS has GCDB data for the area you need, you can download the shapefiles for the applicable townships and look in the coords table. The latitude and longitude are in the North and East fields. The same information is available in the township.LX flat (ASCII) files, which are available from LSIS.
To link the survey corners to the geographic coordinates, use the Point ID. The Point ID naming convention is described in the GCDB User Guide, beginning on page 6, posted at:
http://www.adaweb.net/devserv/survey/GCDBhelp.pdf.
6. How do I change between different coordinates?
You may find the utilities at the following link helpful for converting between different Coordinate systems:
http://www.ngs.noaa.gov/PC_PROD/pc_prod.shtml
7. How do I get only the coordinates for the corners?
You can choose the "Flat File" option when you download. The "Shapefile" option is for displaying the linear features graphically in a GIS viewer such as ArcView or the free ArcExplorer software. You can get the free viewer from:
http://www.esri.com/software/arcexplorer/index.html
If you download the flatfile option, look at the *.lx file with a text editor. A description of the file format is available from the following link, starting on page 6:
http://www.adaweb.net/devserv/survey/GCDBhelp.pdf
8. Where can I get measurements of a given area using the orthophoto?
While you can get a coordinate readout from the Land Survey Information System (http://www.geocommunicator.gov), we did not add any analytic or measurement functionality to the system, in the interest of keeping the interface as simple as possible. If you need to obtain measurements from an orthophoto, there are other tools such as ArcView or ArcExplorer (free) that would be more appropriate to use.
You can get the free viewer from:
http://www.esri.com/software/arcexplorer/index.html
9. I would like to use PLSS data in coverage format. What should I do?
Shapefiles can be converted to coverages using ArcGIS. GCDB coverages in coverage or E00 file format can be obtained on CD by requesting the data via the "Contact Us" link. The cost of the CD is determined by the time required to extract and save the data to CD, plus administrative costs.
10. Where can I find more information related to the content of downloaded data, including the flatfiles?
Documentation related to the content of downloaded data can be found at the following link:
Content of Shapefiles: http://www.blm.gov/gcdb/Standards/index.html
Content of the flatfiles:
Brief description of the flat files (ASCII file) formats
Full Description of the flat files (ASCII file) formats
11. How can I learn more about how to use shapefiles?
The shapefile is an open file format. A technical description is available at the following link:
http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf
There are a number of free shapefile viewers available, including one from ESRI at the following link:
http://www.esri.com/software/arcexplorer/index.html
12. What geographic transformation method was used to convert the GCDB data from NAD27 to NAD83?
The geographic transformation method used to convert the GCDB data from the NAD27 datum to NAD83 datum was "GCS_NAD_27 to GCS_NAD_83_NADCON".
13. Why don't you see the township lines in some areas where there are labels?
The reason you may see the township labels in some areas but don't see the township lines displayed is because there is no BLM data available for that area. If you refer to the availability index, you will see that the areas where labels display without lines are classified as either "Alternate Source" or "No Data available". The labels are displayed for reference, but we don't display the Township lines from the availability index since it was not generated from the BLM GCDB source.
14. How reliable are the GCDB survey-based coordinates?The Public Land Survey System (PLSS) data served to the public via the Land Survey Information System (LSIS) website varies in reliability from township to township. Most of the PLSS data distributed through LSIS is Geographic Coordinate Data Base (GCDB) data in ASCII (flat) file and GIS shapefile format.
In the GCDB flat files, the Reliabilities of each survey-based point is stored in the fields called Northing Error in Feet and Easting Error in Feet. If this field is 40, the survey-based point is expected to exist within 40 feet of the geographic position of the point. This value is determined by the Cadastral Surveyor that abstracts the GCDB data. Factors that effect the Reliabilities include the year of the survey, the reputation of the surveyor, the terrain, and the amount and quality of the Horizontal Control Points with observed geographic positions. See pages A - 20 through A - 23 of Appendix A in the GCDB Software Requirements Specifications section posted at http://www.blm.gov/gcdb/Standards/index.html.
In the GCDB shapefiles, the Reliabilities of each survey-based point is stored in the XACC (X Accuracy) and YACC (Y Accuracy) fields in the COORDS table. See Section 3.4.2 (page 7) of the LSIS Database Design Document in the LSIS Website Section on the same website.
1. What is GIS?
GIS is a Geographic Information System of computer software, hardware and data, and personnel to help manipulate, analyze, and present information that is tied to a spatial location (geographic location). A GIS combines layers of information about a place to give you a better understanding of that place. What layers of information you combine depends on your purpose — finding the best location for a new store, analyzing environmental damage, viewing similar crimes in a city to detect a pattern, and so on.
For more information on what GIS is, visit http://www.gis.com/whatisgis/index.html
1. Where can I find more information on how to get the LSIS into an ArcIMS project?
You may add the LSIS as an internet map service. Internet map services stream live data to the ArcIMS project. Use http:/www.geocommunicator.gov as the server name, and BLM_LSIS as the service name.
Through the “Add Data” dialog window in ArcIMS, choose “Add Internet Server”. From the Add Internet Server dialog window, type in the URL of server: http://www.geocommunicator.gov and choose BLM_LSIS from the list of services.
1. Where can I buy BLM maps and how much would they cost?
Maps depicting recreation, surface and mineral jurisdiction, and wildernesses are normally available at any BLM office. Land status maps range in price from free to $15.50 each.
Come visit our new Public Lands Information Center at 222 N. Central Ave., Phoenix, AZ 85004 (602) 417-9300.
2. What would be the best internet source for Federal status information?
Surface Management Agency (SMA): http://www.geocommunicator.gov Click on Land Manager application.The map service is http://www.geocommunicator.gov
Map Name:BLM_SURFACE_MGT_AGY.
BLM SMA collected at a scale of 1:24,000 - 1:100,000. This may be the "best available" seamless BLM layer for the US.
National Atlas - Federal Lands and Indian Reservations of the United States:
http://nationalatlas.gov/mld/fedlanp.html
The data in this layer has been assembled by the USGS, from data collected from various federal agencies. It is suitable for plotting at a 1:2,000,000 scale or smaller. Polygons have been generalized to the nearest 1 square mile.
3. Where can I find an index of maps for the States?
If you are looking for an index of USGS topographic maps, you can see these from:
http://nationalatlas.gov/
Click the big globe button on the right to "Make Maps.” The Quadrangle index for both 24K and 100K scale are listed under "Reference" map layers. Check the boxes of the items you wish to be displayed. You will need to zoom in to the state level before the quads are displayed. You can turn on other layers for reference and use the identify tool to determine the map name.
If you are only interested in a shapefile, you can find one at http://data.geocomm.com/quadindex/.
1. Am I entitled to free land from the BLM?
No. While that was true at one time, there is no free land.
2. Is homesteading still an option?
Congress abolished homesteading in 1976 with passage of the Federal Land Policy and Management Act, which made it national policy to retain the public lands in Federal ownership. Today, the BLM manages the public lands for all Americans, who enjoy numerous benefits from these lands, including recreational opportunities such as camping, hiking, hunting, and fishing.
3. I have seen an advertisement that says I can obtain low-cost land from the BLM. Is this true?
No. The BLM occasionally sells land - but only at fair market value, as required by law. The advertisement by private companies not associated with the Federal government may ask you to send in money for information about how to buy land for $1.25 an acre (or a similarly low figure). The BLM recommends that you read carefully any advertisement on this subject and be cautious about sending money. The BLM will provide you free and accurate information about land sales.
4. Can you get land if you have a mining claim?
No. Although current law allows you to stake a mining claim on Federal lands that are open to mineral entry, beginning in 1994 and in each subsequent year, Congress declared a moratorium on applying for a mineral patent to a properly located and recorded mining claim. While this moratorium is in effect, the BLM cannot accept mineral patent applications. You may obtain further information on locating mining claims from any BLM State Office.
5. How can I get a copy of a land or mineral patent?
You may obtain microfilm copies of land and mineral patents from any BLM State Office Information Center at a cost of $1.10 per page. In addition, some land patent records are available for selected states on the BLM's Web site at http://www.glorecords.blm.gov/.
6. Where can I get additional information on acquiring land?
You should contact your local BLM office. You can obtain the address from the BLM's Web site, or call 202-452-5125.
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