Web access to the historic topographic quadrangles produced by the U.S.G.S. from 1895 to the present. Some maps covering the San Francisco Bay area are available.
Selected online geologic maps for Alaska, Arizona, California,Hawaii, Idaho, Nevada, Oregon, Utah, and Washington state. Selected Open File Reports in full text are included.
The USGS Map-It is a form based map generator. The form takes longitude/latitude pairs as input and plots them on a Mercator projection map along with land/sea and political boundaries.
The USGS maintains a collection of public-domain software developed by or for the USGS, including cartographic, map production and revision, geospatial metadata, and mapping products access applications.
From the U.S. Geological Survey's (USGS) National Geospatial Program, The National Map is a collaborative effort among the USGS and other federal, state, and local partners to improve and deliver topographic information for the nation.