Digital Line Graphs (DLGs) are vector representations of features on USGS topographic maps by using common scales of 1:24,000 and 1:100,000. (However they can be distributed in large, intermediate, and small scale with a variety of features). Some main features on each layers include boundaries, transportation, surface water, contours, vegetative surface cover, roads and pipelines. For example, the boundaries layer would feature state, county, city, national and state lands such as parks or forests. Hydrography represent water surfaces such as flow/standing water and wetlands. Hypsography features contours and spot elevations.
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