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Our US 48 Basemap collections cover the contiguous 48 US states and were
derived from the USGS data. We assembled this data into complete 48 state
drawings for each feature and then optimized them to reduce the drawings to
manageble sizes.
We offer two products based on this map data:
US48 Basemaps includes all 8 overlay drawings PLUS a higher resolution version
of the States overlay and a 1:15,000,000 scale World Map in Lat/Long.
US48 Basemaps LT includes just the
States and Counties overlays.
Important Information
This map data is not being represented as high accuracy nor is it intended
to form the basis of an accurate mapping / GIS system. We offer the USGS 1:2,000,000
scale DLG data in highly optimized form, to reduce the file size while maintaining
smoothness.
The original DLG data consumes over 125 MBytes in DWG form. We hand sorted
the original data to remove what we considered "minor data", like: short narrow
streams, hiking trails, dirt roads, small lakes and miscellaneous annotations.
During this process, we simplified the layering scheme to uses 2 layer names
per feature (road1 and road2, river1 and river2, etc.). Next we used our Curvefit
applications to dramatically reduce the size of the file without making it
"jagged".
The end result offered below is a coverage of the lower 48 states represented
in 7 files totalling only 22 Mbyte. This data works great for applications
where you are looking at an area larger that the average county. Remember,
this data was never great quality if you look real close. The state boundaries
don't exactly coincide with the county boundaries which don't coincide with
rivers that supposedly run down the same boundary. The biggest advantage to
using this data is that you can access it fairly quickly because it is relatively
compact (miniscule compared to 100K data).
The optimized US data shown below is supplied ROYALTY FREE, in AutoCAD R12
format, Albers projection.
The States overlay - includes closed boundary polylines for 48 states
on one layer. Labels are also included for State names and State capital names.
All polylines are Curvefit Optimized. Here's a zoomed in view.
USGS Quad Key
- A key map for all 100K and 250K USGS Quad maps covering
the lower 48 states. Includes layered polylines and labels. Here's a zoomed in view.
- 1809 USGS 100k Quadrangles
- 488 USGS 250K Quadrangles
USGS 24K Quad Key - A key map showing all of the 24K quad sheets
for the lower 48 states. Includes layered polylines and labels for 53,900
USGS 24K Quadrangles. Here's a zoomed in view.
Counties - Includes closed boundary polylines for 3134 counties. Includes layered labels
for: County Name and County Seat Names. All polylines are Curvefit Optimized. Here's a zoomed in view.
Transportation - Includes layered polylines for:
- 1752 Major Roads
- 4766 Minor Roads
- 567 Major Rail lines
- 698 Minor Rail lines
Here's a zoomed in view.
Rivers - Includes layered polylines for:
- 1504 Major Rivers
- 1717 Minor Rivers
Here's a zoomed in view.
Water Bodies - Includes layered polylines for:
- 96 Major Water Bodies including the Pacific and Atlantic
Oceans and the Great Lakes
- 1783 smaller water bodies
Here's a zoomed in view.
Annotation - Includes text entities for:
- 25286 Town names
- 3208 Water feature labels
Here's a zoomed in view.
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