It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside counties, before cutting through the northern Santa Ana Mountains via Santa Ana Canyon and flowing southwest through urban Orange County to drain into the Pacific Ocean.

Flowing nearly 100 miles from its northernmost reaches at the crest of the San Bernardino Mountains out to the coast near Huntington Beach, the river runs through wild lands, agriculture, parks, towns, and cities, touching the lives of millions of Californians.

Nov 29, 2012 · Rising in Southern California's Transverse Ranges, the Santa Ana is an ancient river; geologists suspect that the river's course predates the uplift of the Santa Ana Mountains, which the river cuts straight through at Santa Ana Canyon.

Apr 30, 2023 · The Santa Ana River stretches over a distance of 110 miles before reaching the Pacific Ocean at Huntington Beach. It is the largest river entirely within Southern California. (A historical marker located in Anaheim in Orange County, California.)

The Santa Ana River Mainstem Project is located along a 75-mile reach of the Santa Ana River in Orange, Riverside and San Bernardino counties. The plan for flood control improvements includes three principal features: Lower river channel modification for flood control along the 30 miles of the Santa Ana River from Prado Dam to the Pacific Ocean.

The Santa Ana River is a major river in southern California, in the United States. It begins in San Bernardino County and flows west about 100 miles (160 km) to the Pacific Ocean, through Riverside and Orange counties. It has a watershed of …

Apr 28, 2024 · The Santa Ana River is the largest river in Southern California. It traverses an area that is home to nearly 2/3rds the state population. However, for many Southern Californians, the river is surprisingly unseen and unknown.

It flows for almost 100 miles from the snowy peaks of the San Bernardino Mountains, through the basin of Riverside to the beaches of Orange County. This unique river is home to hundreds of species of plants and animals and boasts a rich cultural history.

The Santa Ana River Watershed is our major focus. This watershed covers more than 3,000 square miles of San Bernardino, Riverside and Orange Counties, and a small portion of Los Angeles County. It also encompasses the San Jacinto River Watershed.

Mar 28, 2023 · The Santa Ana River, the watershed’s namesake, is the largest river in Southern California, beginning in the San Bernardino Mountains and running almost 100 miles to the Pacific Ocean in Huntington Beach.