Named for exposures at Placer near La Veta Pass, Costilla Co, CO in the San Luis basin. No type locality designated. Applied as a name to a series of black limestone and shale with marine fossils beneath the "Lower Sangre de Cristo conglomerate." Has a maximum thickness of 2,100 ft near Placer. Rests on Leadville limestone or on pre-Cambrian granite. Compared to units assigned to the Weber formation of the Aspen district, CO and to the Hermosa formation of the San Juan region, CO. Cross section. Of Pennsylvanian age.

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

Shown on a correlation chart as of Desmoines [formerly assigned Pennsylvanian] age and equivalent to Hermosa formation of Huerfano Park and to part of Madera formation of New Mexico, to part of Maroon, Minturn, Garfield-Kangaroo formations in other parts of CO. According to author, the top of Veta Pass cannot be placed exactly. Shown on chart as underlying the Sangre de Cristo.

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

Name "discarded" because it implies similarity to the Sangre de Cristo formation. Term Madera formation replaces use of Veta Pass in south-central CO.

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