Grants 1:100000 Quad Hydrography DLGs

Digital line graph (DLG) data are digital representations of
cartographic information. DLG's of map features are
converted to digital form from maps and related sources.
Intermediate-scale DLG data are derived from USGS
1:100,000-scale 30- by 60-minute quadrangle maps. If these
maps are not available, Bureau of Land Management
planimetric maps at a scale of 1: 100,000 are used.
Intermediate-scale DLG's are sold in five categories: (1)
Public Land Survey System; (2) boundaries (3)
transportation; (4) hydrography; and (5) hypsography. All
DLG data distributed by the USGS are DLG - Level 3 (DLG-3),
which means the data contain a full range of attribute
codes, have full topological structuring, and have passed
certain quality-control checks.