The Santa Ana River is roughly 100 miles long and is the longest river completely within Southern California. The Santa Ana River Trail is a partially completed system of trails both paved and unpaved that, when completed, will parallel the Santa Ana from Big Bear Lake to Huntington Beach.
The longest continuous portion is the segment between Prado Dam and Huntington Beach, a paved, multi-use, 28-mile pathway through urban Southern California. This segment is most commonly accessed via Yorba Regional Park, which cuts 6 miles off the distance but offers much easier parking and access to the trail. While not the most scenic ride, the path is 12 feet wide, well maintained, and completely separate from traffic. It is one of the longest paved bike paths in the country that does not traverse surface roads.
The Santa Ana River is a bit of a misnomer since, for most of the year, there is no water running through the riverbed. Only in the mountains does the river flow freely; once into urban areas, the water is diverted for municipal and agricultural use. What little water flows in the lower parts of the river consists mostly of urban runoff and wastewater treatment plant effluent. Despite heavy use and pollution, the river does provide habitat for a wide variety of wildlife, waterfowl and shorebirds, such as Canada geese, ducks, herons, seagulls, and sandpipers.
The path ends at the mouth of the Santa Ana River where it separates Huntington Beach from Newport Beach. Heading north, the path joins the Huntington Beach Bike Trail, and heading south, the path joins the sidewalk along the Pacific Coast Highway. Cyclists can access the Balboa Bike Trail via surface roads. The path is flat with almost no elevation gain or loss and is easily done by novice cyclists. From the beach, you can return to Yorba Regional Park, or arrange for a car shuttle.