Ranging from 430 feet to 1,781 feet in elevation, the park straddles the north end of the Santa Ana Mountains and the southeast portion of the Puente-Chino Hills, which together form the northern end of the Peninsular Ranges in Southern California. This formation interrupts the generally flat Los Angeles Basin with a variety of rolling hills, mountains and canyons on its south and east sides. The hills are a result of uplift and folding along the Whittier and Chino faults.
The Puente-Chino Hills are made up of sedimentary rocks of the Puente Formation, deposited from five to fifteen million years ago. Associated with this formation are petroleum resources that have been explored and exploited in the Los Angeles region since the late 1800s. Fine clay soils are found in these formations, as well as a few areas of alluvial deposits that wash down from the hills and mountains during winter rains.