View west of Iridium Hill, Garfield County, Montana. This short section provided a record of the Ir anomaly in the early discussions concerning the K/T boundary mass extinction (Hartman photo C07207).

View north and northeast of contact between the Hell Creek and Tullock Formations, Garfield County, Montana. This section, located a few miles east of Iridium Hill, is a typical badland exposure in the upper reaches of the Hell Creek and other creeks along the Missouri River (Hartman photo C07260).

View south of upper Hell Creek Formation strata in the Brownie Butte area (on horizon) (Hartman photo C03765).