Version History for USGS Geologic Investigations Series I-2634: 
Geologic Map of the Sedan Quadangle, Gallatin and Park Counties, Montana

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Version 2.0 is the final published version of the geologic map, posted January 2000.
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Version 2.1 posted August 2007
The previous versions of this map misidentified a small polygon near the upper edge 
of this map as formation Qal.  Version 2.1 correctly identifies this formation as Qc.
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