Copperas Mountain is located on the south side of Paint Creek Valley in southwestern Ross County, south-central Ohio (Fig. 1). Erosion by Paint Creek has produced a steep face along the northwestern side of this northerly trending ridge that forms one of the most remarkable exposures in the state (Fig. 2). The site is reached by traveling southwest on U.S. 50 from Bourneville for 1.0 mi (1.6 km), turning south on Jones Levee Road for 0.9 mi ( 1.5 km), continuing west on Spargursville Road for 1.5 mi (2.2 km), turning west and following Orms Road and then Storm Station Road for 0.7 mi (1.2 km), and finally bearing sharply west onto a narrow township road for 0.7 mi (1.2 km) (Figs.1, 2). Vehicles should be parked at the side of the road just north of the cliff, as the road at the foot of the cliff is narrowand treacherous. The cliff area is particularly hazardous in the spring and after periods of rain, due to slick rock and rock falls. The road provides access to the lower portions of the section, while trails lead to the upper parts of the face.