The San Jose Hills are a part of the Transverse Ranges in eastern Los Angeles County, California, marking the border between the San Gabriel Valley and the Pomona Valley. It includes portions of Covina, West Covina, Walnut, Pomona, and San Dimas. To the south, the valley of San Jose Creek (a line followed by the Pomona Freeway) separates the San Jose Hills from the Puente Hills and Chino Hills. History The Tongva village of Tooypinga was located at the base of the San Jose Hills. The village was destroyed by Spanish soldiers prior to 1785 as part of a raid, who frequently conducted sweeps of the Los Angeles Basin abducting children to San Gabriel Mission and raping women. Geology The San Jose Hills are part of the geologic history of Southern California. The San Gabriel Mountains (the Transverse ranges located north of the San Jose Hills) were uplifted by tectonic force as a result of the colliding Pacific and North American plates more than a billion years ago. This tectonic pressure created deeply fractured and fissured sheets of rock that began to shift direction about 25 million years ago. Gradually, a portion of this fissured rock began to uplift from the ocean, forming the Los Angeles Basin. Further folding and fissures helped form other uplifts that include both the San Jose Hills and Puente Hills. These hills, prone to erosion, were formed with their domed appearance while still submerged under water. The San Jose Hills Fault has the possible magnitude of 6.0 to 6.5 and last was active in 1990. The San Jose Hills' highest point is Buzzard Peak at . The highest elevations are composed of conglomerate rock with small, shallow patches of soil. At the bases, silty clay loam dominates. These geologic conditions restrain water absorption towards the rockier higher elevations, which allow runoff to hydrate the base, creating a more habitable (friendly) environment for plants. Because of the transverse (east-west) orientation of the range, this effect is pronounced on the north slope due to the lower rates of evaporation caused by sunlight directed from the south. Plant communities and wildlife The San Jose Hills are diverse with unique and rare plant communities. The dominant plant community is coastal sage scrub, known for its high adaptations for long dry summers and is drought deciduous. Prickly-pear cactus can also be found there. Above , chaparral makes its appearance, which