Aberdeen Volcanic Field and Vicinity

This area includes not only the Aberdeen Volcanic Field, which lies roughly between Division and Taboose Creeks on the south and north, Highway 395 on the east, and the wall of the Sierra on the west, but two large areas to the north, one surrounding Red Mountain, the other Crater Mountain.

In the Aberdeen field a row of red cinder cones curves along the base of the Sierra to the north and south of Goodale Creek. These cones are located on the main Sierra boundary fault. Black basaltic lava from these and other cones and vents has flowed over the alluvium of the valley floor. Four distinct flows have occurred within the past 200,000 years, the latest possibly in the Recent period. In Sawmill Canyon, to the south of Division Creek, there is a lava flow dating roughly to 100,000 B.P. that has been cut to a depth of 45 meters (15 feet) by the stream. Upstream, a moraine rests on this flow, and further upstream the flow rests upon an earlier moraine.

Red Mountain rises some 200 meters (620 feet) above the general terrain. It is an explosion on cinder cone, nearly perfectly formed, which erupted through a granite hill on a fault parallel to the main boundary fault. The cone is made of reddish fragments, mostly less than 15 centimeters (6 inches) in size but including some bombs up to 120 centimeters (48 inches) across. The mountain has suffered some erosion, and portions of its lower slopes have been buried by alluvium.

Crater Mountain, 10 kilometers (6 miles) to the north, stands 600 meters (2,000 feet) above the valley floor and has a double crater at the summit. It was also formed by eruptions through existing granite mountains and lies on the same fault as Red Mountain. Portions of the granite not covered by the lava flow are visible on the northwest slope. (To the immediate north are several granite knobs protruding above the flow.) On the west slope of Crater Mountain is a lava cave with several small rooms.

A number of fault scarps are visible in the alluvium; Red Mountain stands at the south end of a clearly defined scarp dating to the 1872 earthquake.

Vegetation in the area is primarily sagebrush scrub, with some riparian along the creeks. Among the plant present are big sagebrush, Artemisia tridentata, antelope bush, Purshia glandulosa, desert peach, Prunus andersonii, Lupinus excubitus, and Ceanothus greggii var. vestitus.

Sawmill Canyon supports an excellent example of the sagebrush scrub community, including some very large Artemisia tridentata. A disjunct colony of Rocky Mountain narrow-leaved poplar, Populus angustifolia, is found at the mouth of Division Creek, near Scotty Spring. The cinder cones and lava areas are inclined to act as "hot houses" for plant life in the spring.

Much of this area is utilized by the Goodale herd of tule elk, Cervus nannodes. (See Tule Elk National Wildlife Refuge).

Integrity: A few roads wander through the area and there has been some quarrying, particularly on Red Mountain. For the most part, the area is relatively undisturbed.

Use: Educational, research, observational. Ref: Hinds, Norman, 1952. Evolution of the California Landscape. Calif. Div. Mines Bull.152, pp.64-69.

April 1976