Introduction

The geologic and structure map of the Choteau 1 x 2 degree quadrangle (Mudge and others, 1982) was originally converted to a digital format by Jeffery T. Silkwood (U.S. Forest Service) and completed by U.S. Geological Survey and contractors at the Spokane Field Office (WA) in 2001 for input into a geographic information system (GIS). The resulting digital geologic map (GIS) database can be queried in many ways to produce a variety of geologic maps. Digital base map data files (topography, roads, towns, rivers and lakes, etc.) are not included: they may be obtained from a variety of commercial and government sources. This database is not meant to be used or displayed at any scale larger than 1:250,000 (for example, 1:100,000 or 1:24,000). The digital geologic map graphics and plot files (chot250k.gra/.hp/.eps and chot-map.pdf) that are provided in the digital package are representations of the digital database. They are not designed to be cartographic products.

 Description of files available to download

 File size

 README (UNIX ASCII) file listing all files available for download

README (DOS ASCII)

8 kB

8 kB

 I-1300 text in Portable Document Format (PDF)

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784 kB

Complete digital data package as a .zip file

9.8 MB

Complete digital data package as a .tar.Z file

     Utilities to extract TAR and GZIP files on your Windows or Macintosh

13.1 MB

16 kB

Map File in Portable Document Format (PDF)

Map scale: 1:250,000

Page size: approximately 36" x 28"

1.5 MB