San Gabriel River Fluvial Landscape

Fluvial Landscape: Chino Hills State Park

Chino Hills State Park is located in the Chino Hills, which are in the foothills of the Santa Ana Mountains. Chino Hills State Park is located almost entirely in the city of Chino Hills, California. Chino Hills State Park is a link in the Puente-Chino Hills Wildlife Corridor, which enables migrating wildlife to retain their normal migratory patterns despite widespread human habitation in the surrounding area. It provides open space for human recreation, but its most important functions are to provide a natural habitat for native vegetation, water resource protection, and wildlife protection.

Chino Hills State Park is just over 14,000 acres and can be found near where Orange, Riverside, and San Bernardino Counties intersect. The park includes some of the Santa Ana Mountains and a significant portion of the Puente-Chino Hills Located in the hills; it is no surprise to find a wide range of elevations in the park. The elevation in the park ranges from 430 feet to 1,781 feet (California State Parks). The Puente-Chino Hills is the northern end of the Peninsular Ranges in Southern California, a range that interrupts the otherwise flat Los Angeles Basin with rolling hills, mountains, and canyons (California State Parks). These geographical features are the result of uplift and folding along the Whittier and Chino faults. The Puente-Chino Hills consist of sedimentary rocks of the Puente Formation (California State Parks). These rocks were deposited 5 to 15 million years ago (California State Parks). In addition o the rocks, one can find fine clay soils and some alluvial deposits that wash down from the hills and mountains during winter rains (California State Parks). This wide variety of soils and the alluvial deposits means that one can find a wide variety of minerals in Chino Hills State Park. The area has been used for petroleum and natural gas exploration, and has substantial subsurface minerals. In addition, the alluvial deposits make it possible to discover a wide variety of minerals within the park's boundaries, notably copper.

Chino Hills State Park features a number of water types. There are a substantial number of creeks in the park, and some of these are seasonal, dependent either upon winter rains or the spring melt of water coming down off the mountains and hills. There are not standing above ground water features like lakes, but there may be seasonal ponds or other collections of water, depending on runoff patterns, rainfall, and other features. There are a number of different underground water sources, also known as aquifers or water basins, that may be impacted by conditions across the park, since these aquifers, even if not located in the park, are fed by the same winter-run off as the water sources in the park. These aquifers include: Lower Canyon Basin, Lytle Basin, Devil Canyon Basin, Rialto-Colton Basin, Bunker Hill Basin, Yucaipa Basin, Beaumont Basin, San Timoteo Basin, Riverside North Basin, Riverside South Basin, and Arlington Basin.

The Chino Hills are in the California chaparral and woodlands ecoregion of the California Floristic Province. Native vegetation in the park falls into three main categories: chaparral, oak woodland plants, and native grasses, but there is tremendous diversity in the park's vegetation. Chino Hills State Park has several different kinds of vegetation in each of its major habitats. In the creek zones, cattail stands, as well as willow and sycamore woodlands with understories of wild rose, stinging nettle, and mule fat provide habitats for numerous animals. Live coast oaks are near the water sources, giving way to Southern California black walnut trees. The Tecate cypress is found in some parts of the park, specifically Coal Canyon. The park also features scrub and chaparral communities, which have coastal sage scrub, California sagebrush, California buckwheat, purple stage, laurel sumac, and toyon (California State Parks). The grass in the park provides a good example of invasive species. "Most of the grassland in the park is non-native annual European grasses that were introduced here during the early ranching years. However, grassland species native to California, such as purple needle grass and giant rye can be found among the annuals. An active grassland restoration program in the park is restoring native grassland to its more natural and dominant state" (California State Parks).

The climate in the park is typical of the climate in other parts of the Inland Empire area of California. The climate is temperate, so that it is warm in the summers, with temperatures usually in the 70s, and cool in the winter, with temperatures in the 50s. August is the warmest month of the year and January is the coldest month of the year, but temperatures are mild. Obviously, higher elevations experience broader temperature ranges. There is a moderate difference in daytime and nighttime temperatures. Rainfall is distributed throughout the year, but February tends to be wetter than other months. The area has relatively low humidity, but is not arid.