South margin of La Garita caldera 8. Within the caldera, a thick lava sequence of dark Huerto Andesite and underlying Fish Canyon Tuff (light-colored rock exposed along lower slopes of valley) was deposited against the caldera wall to south. Light-colored rock along right (north) part of ridgecrest is Carpenter Ridge Tuff, above the intracaldera Huerto Andesite. The eroded south caldera rim is marked by Sugarloaf Mountain (rounded light-colored mountain above geologist in foreground), where proximal outflow Fish Canyon Tuff overlies dark intermediate-composition lavas and breccias of the Conejos Formation. The grassy area in foreground is weakly welded top of Fish Canyon Tuff. View to west from Puerto Blanco (Palomino Mountain quad). Photograph by P.W. Lipman.