Sources of Maps
USGS Topographic Maps
(7.5 minute) are sold at some bookstores and outdoor/camping shops, or they may be
obtained from USGS Map Sales, Box 25286, Denver, CO 80225. Phone (303) 202-4700.
USGS
Land Cover and Land Use Maps
(scale 1:100,000) may be obtained from the Colorado address above.
National
Wetlands Inventory Maps
(scale 1:24,000) may be obtained from the Mapping Center, USGS, 507 National Center,
Reston, VA 22092. Phone (703) 648–6892.
Aerial
Photographs (various scales) are available from USDA Aerial Photography Field
Office, 2222 West 2300 South, P.O. Box 30010, Salt Lake City, UT 84130–0010.
Agricultural
Stabilization and Conservation Service (ASCS) and Natural Resources
Conservation Service (NRCS, formerly the Soil Conservation Service) offices in
your county have aerial photos that you may look at. Check the phone book under
"United States Government, Agriculture Dept. of" for the location and phone
number of the office in your county.
Land management agencies (including
federal and state/provincial offices) may have aerial photographs that you can photocopy.
Canadian Topographic
Maps The Canada Map Office no longer distributes maps directly to the public. They
recommend you purchase National Topographic System maps from any of over 900 map dealers
across Canada, the United States, and overseas. To find map dealers in your area, please
consult the Yellow Pages under "MAPS,"
or contact any Regional Distribution Centre. See the Centre for Topographic Information, Ottowa
web site for more details.
MAPPING RESOURCES ON
THE WEB
If you can't find sources of maps in
your area, you may want to try the worldwide web. The following web sites may be of use.
For the United States
http://www.topozone.com This site has topographic maps for the entire
United States. You can select different scales at the top of the map, and you can select
how latitude and longitude are displayed below the map (select D/M/S for
degrees/minutes/seconds). As you move the mouse over the map, latitude and longitude are
displayed in the status bar at the bottom of the screen.
For Canada
http://geonames.nrcan.gc.ca/english/Home.html This site does not have topographic maps, but it
does have road maps. Query by name and then submit search. Then click the button under
"details," and then click the "Earthscape II" icon. As you move the
mouse over the map, latitude and longitude ae displayed at the bottom of the map in
decimal degrees.
Determining
Latitude and Longitude
via the World Wide Web
One way to determine
latitude and longitude coordinates is to use one of the map servers available on the
internet.
On all map servers, you
can point and click to zoom and re-center the maps to find the location you want. Most map
servers start with a map of the entire US. You can zoom in on the maps to a scale where
streets are labeled with names.
On most map servers, you
can zoom into an area by searching for a street address.
Most map servers provide
maps only for the US.
Longitude values from
these Web sites may be negative. This is because, technically, the western hemisphere is
defined as having negative longitudes. For daily use, we drop the negative sign for
longitudes.
Please let us know if you have any URLs for other map
servers, especially ones covering Canada.
Silicon Mapping
National Map Server
http://imap.chesapeake.net/cgi-bin/webmapper
This is a very good one to try. This server will give the latitude and longitude of a
location in decimal degrees to 5 decimal places. This server usually fairly fast.
US Census Bureau
Tiger Map Server
http://tiger.census.gov/cgi-bin/mapbrowse-tbl
This server gives latitude and longitude to 5 decimal places. Lab staff experience with
this server is that it is heavily used and very slow.
Maps On Us
http://www.mapsonus.com/
This server will give latitude and longitude, but it takes a bit of fiddling around to get
them. Click on "Maps" on the first page. Then click on "General
Options" before entering the address. On the "Maps On Us: General Options"
page click on the "Show Latitude & Longitude" box. Then, click on the
"Set General Options" button. Then type in the address of the location you want
to see. Next click on "Draw New Map" then click on "Draw Map" under
"Draw Map Of These Coordinates."
Map Blast
http://www.mapblast.com/
When last checked, this server did not provide latitude and longitude.
Map Quest
http://www.mapquest.com/
This map server does not provide latitude and longitude of locations, though they claim
they will have Canadian data available soon.
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