The San Luis Hills' highest point is Flat Top, elevation 9,206 feet (2,806 meters).

[7] They are north of Colorado State Highway 142 and west of the Rio Grande in Conejos County.

[11] The basalt is underlain by Oligocene andesite and dacite volcanic deposits of the lower Conejos Formation.

However, some informal hiking trails exist, and mountain climbing and bouldering are possible, especially around the Manassa Dike on south side of Flat Top.

The plan is to transfer the land to Costilla County, which will manage it for wildlife habitat, agriculture, and public open space.