Motte Rimrock Reserve
The Motte Rimrock Reserve, established in 1976, occupies a broad, rocky plateau on the western edge of the Perris Valley in southern California. Located equidistant between the climatological influences of the Pacific Ocean and Colorado Desert the Reserve supports an unusual mix of habitats. Riversidean sage scrub a vegetation association unique to southern California covers most of the Reserve with other areas supporting coastal-desert transitional grassland and willow riparian thickets. Granite rock outcrops represent the dominant landscape feature. Six seasonal springs add to the diversity of the landscape. The habitats harbor a diverse array of flora and fauna including 192 vascular plant, 3 amphibian, 22 reptile, 150 bird, and 23 mammal species. Ten rare species occupy the Reserve including two with federal listings: the endangered Stephens kangaroo rat (Dipodomys stephensi) and the threatened California gnatcatcher (Polioptila californica). In addition to biological diversity the Reserve also protects important archaeological sites, including an unexcavated ceremonial site and well-preserved pictographs.
During the second half of the 20th Century southern California added approximately 9 million inhabitants. Recent population growth estimates project the influx of an additional 3 million by the year 2030. The progressive suburban sprawl exacerbates an existing conflict between the need to provide services for an expanding populace and the need to conserve habitats and native species from local extirpation. As the human population grows the Motte Rimrock Reserve and other protected lands in the western Riverside County region will take on added importance. The Reserve protects native flora and fauna, serves as a field laboratory for biologists addressing questions that involve ecology, genetics, conservation biology, and biogeochemistry, and serves as a living classroom for students ranging in age from K through 12 through advanced undergraduate.