1. Geologic map of the Clifton House quadrangle, showing fossil zones in the Pierre Shale, Colfax County, New Mexico Yale Public content 1994. 2002-06-01T04:00:00Z. 2012-07-17T20:19:38Z. Geological Survey (U.S.). The Survey ; For sale by Map Distribution. English. Public. New Mexico and Colfax County.