Bristol Head 10. View of Bristol Head from the southeast (near Bristol Head-Workman Creek quad boundary). Tilted andesitic lavas of the Conejos Formation and overlying Masonic Park Tuff and thick intracaldera Fish Canyon Tuff (forming prominent cliff in middle distance) are interpreted as the floor of La Garita caldera, tilted by postcollapse resurgent uplift. High point on Bristol Head (in distance, on left) is capped by andesite of Bristol Head, overlying thick flows and breccias of Huerto Andesite, which accumulated against west wall of La Garita caldera. Photograph by P.W. Lipman.