The type locality of the unit is in Ventura County, on the east side of Rincon Mountain, where the formation is exposed in the south-flowing Los Sauces Canyon, north of U.S. Highway 101 and in the vicinity of the Rincon Oil Field. The unit is mapped from Ventura County westward along the south slope of the Santa Ynez Mountains, as well as on portions of the north slope. It also occurs in a few places north of the Santa Ynez Fault, but outcrops nowhere north of the Santa Ynez River. In the subsurface it frequently is found in well cores, underlying the Monterey Formation and overlying the Vaqueros Formation. At the ground surface, the contact with the Vaqueros is obvious along the south slope of the mountains, for it is almost always defined by the line dividing the rounded, grassy foothills from the more rugged, chaparral-covered sandstones upslope.