San Benito Mountain Natural Area

This is the only area where Coulter pine, Pinus coulteri, Jeffrey pine, Pinus jeffreyi, and gray pine, Pinus sabiniana, are found growing together.

Coulter pine is the dominant tree in the forest and open pine woodlands. This stand is the most extensive population on serpentine. Although only a few Jeffrey pines are found within the area, they are common along upper Sawmill Creek and lower Clear Creek. This locality is the only one in the south Coast Range where Jeffrey pines are found. The nearest stands are in the Sierra Nevada 145 kilometers (90 miles) east and in the San Rafael Mountains 200 kilometers (125 miles) south.

Hybrids of Pinus coulteri and Pinus jeffreyi are scattered along the lower slopes of the eastern portion of the area. Gray pine is common in the chaparral and pine woodland. The largest mixed stand of gray and Coulter pines in the State is found here.

Incense cedar, Calocedrus decurrens, also occurs here in a disjunct stand. The nearest stands are 64 kilometers (40 miles) west in the Santa Lucias, 168 kilometers (105 miles) southeast in the Sierra Madre Range, and 145 kilometers (90 miles) east in the Sierra Nevada. The tree is common in the forest and woodland.

Chaparral on the area is dominated by leather oak, Quercus durata, and two manzanitas, Arctostaphylos glauca and Arctostaphylos pungens. A number of understory plants in the woodland and chaparral are endemic to serpentine in the south Coast Ranges. Several species found here are uncommon in the south Coast Ranges on any soil type and include Allium burlewii, Boschniakia strobilacea, Castilleja miniata, Linum lewisii, and Pediomelum californicum. The rare Camissonia benitensis and Layia discoidea, though not found in the area, have been collected nearby.

Soil parent materials on the area are almost entirely ultrabasic. Locally they are characterized by a highly sheared, slickentite form of serpentine that results in "bald" slopes that support no vegetation but widely spaced pines.

An interesting disjunct population of the sagebrush lizard, Sceloporus graciosus, occurs here.

Integrity: A dirt road passes through a portion of the area. The Calocedrus was logged approximately 50 years ago.

Use: Research, education.

Ref: Griffin, James, 1974. A Strange Forest in San Benito. Fremontia. Vol. 2, No. 1, p. 11-15 illus.
Bolgooyen, T. G., 1970. The Sagebrush Lizard, etc. California Fish and Game No. 54, p. 310-311.
Griffin, J. R., 1971. Vascular Plants of the San Benito Mountain Natural Area. Bureau of Land Management, Folsom, California. Mimeo.
Zoebel, B., 1951. The Natural Hybrid between Coulter Pine and Jeffrey Pine. Evolution Vol. 5, p. 405-413.

February 1975