Anza-Borrego Desert State Park

This, the largest of the California state parks, includes a wide variety of communities, ranging from alkali sinks and desert washes to a pinyon pine woodland.

In much of the park the dominant community is the creosote bush scrub, with Larrea tridentata, burro weed, Ambrosia dumosa, incienso, Encelia farinosa, Mormon tea, Ephedra californica, and desert ragweed, Hymenoclea salsola, among the dominants. The century plant, Agave deserti, and various cacti including jumping cholla, Opuntia bigelovii, beaver-tail cactus, Opuntia basilaris, barrel cactus, Ferocactus cylindraceus, and ocotillo, Fouquieria splendens, are abundant, with the latter occurring throughout the park.

In the desert wash community the smoke tree, Psorothamnus spinosus, desert ironwood, Olneya tesota, and palo verde, Cercidium floridum, are prominent. The salt-bush, Atriplex polycarpa, desert holly, Atriplex hymenelytra, and iodine bush, Allenrolfea occidentalis, are present in the alkali-sink community.

Two pinyons, the single-leaved, Pinus monophylla, and the Parry, Pinus quadrifolia, are found in the higher wooded areas. Along the springs and the few permanent streams there is a riparian community which includes, variously, willow, Salix spp., desert lavender, Hyptis emoryi, desert willow, Chilopsis linearis, and arrowweed, Pluchea sericea, among others.

There are a number of groves of the California palm, Washingtonia filifera, the largest containing several score. Of particular note is the rare and unusual elephant tree, Bursera microphylla, which, though common in Baja California, is known from only a few localities in the State, two of which are in the park.

Of the more than 500 species of plants found in the park, at least 10 are considered rare; they are, in addition to the Bursera, Ayenia compacta, Berberis fremontii (= Berberis higginsae), Cheilanthes parishii, Mimulus aurantiacus (= Diplacus aridus), Galium angustifolium var. borregoense, Heuchera brevistaminea, Machaeranthera lagunensis, Pholisma arenarium, and Salvia eremostachya. Two others, Pilostyles thurberi and Mentzelia hirsutissima var. stenophylla, are found nearby.

There is an abundance of desert animals in the park which includes much of the California range of the rare Peninsular bighorn sheep, Ovis canadensis cremnobates. Other mammals include the bobcat, Lynx rufus, kit fox, Vulpes macrotis, gray fox, Urocyon cinereoargenteus, badger, Taxidea taxus, as well as a number of rodents. Over 150 species of birds have been sighted in the park, and numerous reptiles as well.

The geology of the park is complex; it includes a number of faults and is traversed by the Agua Caliente Fault Zone. Geological formations range from the granitics of the Mesozoic to Quaternary alluvium. The highly eroded Pliocene-Pleistocene non-marine badlands are noted for their fossil sequence. Such Central and South American forms as a ground sloth, Megalonyx, and a porcupine have been found here, as have numerous northern forms including mastodons, several camels, horses and antelopes, among others. Of note is the vulture, Teratornis incredibilis, whose wingspan is estimated at 5 - 5.5 meters (17 -18 feet).

Integrity: Portions are developed for park use. Much of the area is virtually undisturbed, though there are traces of mining, etc. Several historical trails and sites are found within the park.

Use: Research, educational, observational, light recreation.

July 1976