Named as the upper member of Parkman sandstone (rank raised) of Mesaverde group (rank raised in report area). Type well designated as the Farmers Union #1 Government-Ferguson in SE, SE, sec. 13, T 49 N, R 76 W, Campbell Co., WY in the Powder River basin. Isopach map shows member as a lenticular body extending from T 48 N, R 75 W northwest to T 50 N, R 76 W. E-log cross section. Overlies the newly named Dead Horse Creek member of Parkman. Underlies shale tongue of Pierre shale. Defined as the interval between 6,965 and 7.014 ft in the type well. Is a 10-30 ft thick uniform, clean, littoral bar sandstone. The sandstone consists of about 50 % quartz and 50 % of a mixture of feldspar, mica flakes, and traces of heavy minerals. Some cherty and silicified grains. Some altered volcanic and metasedimentary rock fragments. Member includes what has been called the "Low SP zone", a 10-20 ft thick sandy shale at base of member. Late Cretaceous age.

Source: GNU records (USGS DDS-6; Denver GNULEX).