Del Valle Regional Park: a five-mile lake south of Livermore with swimming, trout fishing, cabins and the Ohlone Trail

The East Bay Regional Park District calls Del Valle "like a lakeside resort only 10 miles south of Livermore." The park centers on Lake Del Valle, a five-mile-long lake in a valley of oak-covered hills, with 4,395 acres of land around it for hiking, horseback riding and nature study.

The lake

Lake Del Valle is a reservoir on Arroyo Valle in the Diablo Range, formed by Del Valle Dam. Construction started in 1966, the dam was finished in 1968 and the regional park opened in 1970, according to Wikipedia. The earth-fill dam is 230 feet high and 880 feet long. The lake is part of the State Water Project's South Bay Aqueduct and serves partly as off-stream storage.

Swimming, fishing and boating

Swimming is allowed in designated areas south of the boat ramp. It is also allowed north of the ramp, but no lifeguards are on duty there. The park district says the lake is stocked regularly with trout and catfish and also has largemouth and smallmouth bass, striped bass and panfish. A state fishing advisory covers mercury levels in fish from the lake. Blue-green algae has been an issue in the past; swimming was banned during the 2015-2016 winter.

Any size boat can use the public ramp, but every boat must pass an invasive mussel inspection. The speed limit is 10 mph on the whole lake, and hydrofoils and e-foils are banned. Motorboats and patio boats can be rented at the East Beach marina, and kayaks and paddleboards are rented seasonally.

Camping and trails

The family campground has 150 sites, including two accessible ones; 21 have water, sewer and electric hookups. There are also five cabin sites, group camps and a small horse camp. Del Valle is the eastern gateway to the Ohlone Wilderness Trail, 28 miles of backcountry trail toward Sunol and Mission Peak. The Arroyo Road staging area at the north end is small and fills up on weekends. It connects on foot to Sycamore Grove Park in Livermore.

Hours and fees

In November and December the gates are open 7 a.m. to 6 p.m. Parking is $5 per vehicle, and there is no parking fee at the Arroyo staging area. From April through Labor Day there is a flat $10 weekend and holiday entry fee. The visitor center, on the lake's west side, is open Fridays, weekends and most holidays from 10 a.m. to 4 p.m. from September through May. The park district says the park is open with limited amenities: use caution on storm-damaged trails, and the swim beach food concession remains closed.

Related: tarantula season at Del Valle and Sunol.