1. Bedrock geologic map and coal sections in the Buffalo 30ʹ x 60ʹ quadrangle, Johnson and Campbell counties, Wyoming Yale Public content 1990. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by Map Distribution. English. Public. Wyoming, Buffalo Region, Campbell County, and Johnson County.