Kwage Mesa is on the way to Los Alamos from Espanola and is part of the Jemez Mountains. This formation is about 300 meters thick and was laid down in one explosion. Mt. St. Helens was a wimp, its maximum ash fall was half a meter. This was taken from a similar mesa on the other side of Pueblo Canyon. Notice that the Tuff at the bottom is well welded and the cliff is shear. The tuff on top is weakly welded and subject to relatively rapid erosion.