Mount Scott 4. View of Mount Scott looking southeast from Rim Drive, where the road traverses the southern of two thick flows of andesite of Grotto Cove (unit agc) near a picnic area. Mount Scott is a stratovolcano composed entirely of dacite (unit ds; ca. 420 ka) erupted from low lava fountains. Its hydrothermally altered interior is exposed in the cirque on right. Smooth dark cliff in foreground is vitrophyric north flank of the Redcloud Cliff rhyodacite flow (unit re; ca. 27 ka), where lava chilled against glacial ice and was subsequently sculpted by glacial action. Forested mesa in middle distance between Mount Scott and the Redcloud Cliff flow is Scott Bluffs, a coulee of dacite of Pumice Castle (unit dc; 71±5 ka, weighted mean). Photograph by Charles R. Bacon.