The geologic and structure map of Choteau 1 x 2 degreequadrangle (Mudge and others, 1982) was originally converted toa digital format by Jeff Silkwood (U.S. Forest Service andcompleted by the U.S. Geological Survey staff and contractor atthe Spokane Field Office (WA) in 2000 for input into ageographic information system (GIS). The resulting digitalgeologic map (GIS) database can be queried in many ways toproduce a variey of geologic maps. Digital base map data files(topography, roads, towns, rivers and lakes, etc.) are notincluded: they may be obtained from a variety of commercial andgovernment sources. This database is not meant to be used ordisplayed at any scale larger than 1:250,000 (e.g. 1:100,000or 1:24,000. The digital geologic map graphics and plot files(chot250k.gra/.hp/.eps and chot-map.pdf) that are provided inthe digital package are representations of the digitaldatabase. They are not designed to be cartographic products.