Lava Beds National Monument
Map SatelliteExamples of most of the volcanic features found in the Modoc Plateau occur in the Lava Beds National Monument. These include cinder cones, spatter cones, explosion craters, chimneys and 293 known lava tubes.
Originating in the late Pleistocene, the center of-volcanic activity was in a shield volcano lying to the south in the Medicine Lake Highlands. Most of the flows are pahoehoe type (smooth or ropy) but there are occasional aa flows (broken, clinkery lava). Some of the flows perhaps date as recently as 1,000 years B.P. Of the 293 tubes, only 190 have been explored to any great degree and each exhibits a diversity of form and surface detail; many have lavacirles. Fossil mastodon and camel remains have been found here. Approximately 100 of these tubes are ice caves.
Gillem Bluff, along the western edge of the monument, is a fault scarp. West of the scarp there are older, Tertiary volcanics.
Vegetation is generally sparse but includes three communities. Over half of the area is a Great Basin sagebrush scrub community with basin sagebrush, Artemisia tridentata, and antelope bush, Purshia tridentata, the dominants, interspersed with several bunchgrasses including Pseudoroegneria spicata ssp. spicata and Festuca idahoensis.
Much of the southern portion of the area is covered by a northern juniper woodland, with Western juniper, Juniperus occidentalis, dominant. In this area much of the understory is Artemisia tridentata.
In the higher elevations along the southern border there is a ponderosa pine - white fir forest with Pinus ponderosa, Abies concolor and Western white pine, Pinus monticola.
The rare plant Agastache parvifolia occurs in the area.
Animal life is typical of the region and includes sage grouse, Centrocercus urophasianus, occasional blue grouse, Dendragapus obscurus, bald eagle, Haliaeetus leucocephalus, and pronghorn, Antilocapra americana. The bighorn sheep, Ovis canadensis, once common in the area but extirpated early in the century, has been reintroduced.
Integrity: There are numerous trails and roads in the area as well as park facilities. Some grazing has occurred, but much of the area is undisturbed.
Use: Present.
Ref: Perry, B. and S. Schlegel, 1973. The Life of Lava Beds, 32 pp. Washington U. S. G.P.O.
March 1980
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman
