1. Stratigraphic framework and coal resources of the Upper Cretaceous Blackhawk Formation in the East Mountain and Gentry Mountain areas of the Wasatch Plateau coal field, Manti 30ʹ x 60ʹ quadrangle, Emery, Carbon, and Sanpete counties, Utah Yale Public content 1987. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by Map Distribution. English. Public. Utah, Emery County, Carbon County, and Sanpete County. Cretaceous.