Reinecker Ridge, east of Fairplay, is a prominent north-south trending ridge rising almost 300 m to 3200 m altitude above relatively flat South Park, Colorado. The bulk of the ridge is comprised of South Park Formation, lower volcaniclastic stratigraphic member (lower Paleocene). It is a poorly sorted and poorly lithified, polymictic, coarse-grained conglomerate yielding isotopic ages ~64-67 Ma. The ridge forms the eastern border of the Buffalo Peaks Ranch, the site of the Rocky Mountain Land Library.