Simi Hills

Two plant communities dominate the area, coastal sage scrub and chaparral. The scrub includes Artemisia californica, Salvia spp. and Rhus spp. In the chaparral, Eriodictyon crassifolium, Heteromeles arbutifolia, Fraxinus dipetala and Quercus berberidifolia are among the elements of the community. There is a small amount of riparian association along the creek beds, with sycamore, Platanus racemosa and Quercus spp. present.

The rare Hemizonia minthornii is known from only this locality. This plant is of interest as the closest mainland relative of the Hemizonia on the coastal islands.

Animal life is abundant and includes such birds as the rock wren, Salpinctes obsoletus, and the rufous-crowned sparrow, Aimophila ruficeps.

Within the area are found upper Cretaceous marine sediments, primarily sandstones, Paleocene marine sediments including the Simi conglomerate with sandstones, and Eocene sedimentaries. Here there is no break between the invertebrate marine fossil fauna of the Mesozoic and Cenozoic eras. East of the summit, cuts provide good exposures of structures attributable to turbidity flow–convolute bedding, pull-aparts, flow clasts and graded bedding–formed in deep water by submarine landslides.

Integrity: A freeway cuts through the pass and housing developments are encroaching; however, much of the area is relatively undisturbed.

Use: Private

Ref: Carlquist, Sherwin, 1965. Island Life. Nat. Hist. Press, Garden City, N. Y. pp. 115-118.

March 1977