It is exposed only in a small area of the northernmost Sacramento Mountains, and transitions to mostly continental red mudstones some 1,000 feet (300 m) thick before abruptly pinching out to the southeast.

[1] The formation is interpreted as cyclic sequences of terrestrial and shallow marine carbonate rocks deposited on a narrow shelf lying between the Pedernal Uplift to the east and the Orogrande Basin to the west.

[1][2] Cycles are generally transgressive (recording the advance of the sea), with basal conglomerate giving way to increasingly fine sandstone, siltstone, and shale and finally limestone.

[2] The limestone beds of the formation are highly fossiliferous,[1] containing bioclastic remains from all the main late Paleozoic shallow marine biotic groups.

[1][3][4] Microfossils of the formation include the cyanobacteria such as Girvanella, calcivertellid foraminiferans, and phylloid (leaflike) algae such as Eugonophyllum.