A Digital Line Graph (DLG) is digital vector data representing cartographic
information. DLGs contain a wide variety of information depicting geographic
features (for example, hypsography, hydrography, boundaries, roads, utility
lines, etc). DLGs are derived from hypsographic data (contour lines) using
USGS 7.5-minute, 15-minute, 2-arc-second (30- by 60-minute), and 1:2 million-scale
topographic quadrangle maps.
The 7.5- and 15-minute DLGs are within the large-scale category; the
2-arc-second DLGs are within the intermediate-scale category, and the
1:2 million-scale DLGs are within the small-scale category.
To learn more about DLGs, check out the
at the Crater Lake Data Clearinghouse Web site.
The San Francisquito Creek project covers six USGS 7.5-minute quadrangles.
These six quads have been mosaicked together for your convenience of viewing
and analyzing the information throughout the area. Data are reprojected
to one standard projection (UTM NAD27 zone 10 meters). Click on
the following link to download the data:
hyd.zip (2.2 MB uncompressed)
-- Files containing drainages and water bodies.
hyp.zip (29 MB uncompressed)
-- Files containing contour lines.
roads.zip (12 MB uncompressed)
-- Files containing roads and trails.
Links open in a new window.