The West Potrillos

The West Potrillos are a volcanic mountain chain located in the largest wilderness study area in Southern New Mexico. Because of the isolated desert location, relatively low elevation, and absence of high peaks this is a seldom visited region.

The West Potrillo Mountains consist of a broad topographic high composed almost entirely of volcanic materials. The range rises 400 to 800 feet above the surrounding desert floor and is capped by numerous cinder cones that reach elevations of over 5,000 feet. Cinder cones are the most abundant volcanoes in the West Potrillo region and over 150 cones are present. The cones range from 200 to 500 feet in height above the topographic high caused by coalesced basalt lava flows and cinder cone eruptions. Typically the cones are composed predominantly of cinders, bedded cinder, lava bombs, sometimes with a partial to complete spatter rim at the top. Often cinder cones occur in complexes with multiple lava vents. The age of the cinder cones is around 150,000 to 200,000 years (Hoffer, 1976).

The overall plan for this trip is to traverse the range, examine anything of interest, and visit all of the cinder cones that appear, based upon USGS topographic maps, to have intact craters. Five intact craters are clearly marked on the maps.