Calero County Park

Calero County Park combines a year-round boating reservoir with a large back country. Calero Reservoir is open to both power and limited-power boats every month of the year, for power boating, sailing, water skiing, jet skiing, and fishing. Boats launch from 8 a.m. and must be off the water 30 minutes before sunset, and boaters pay launch and inspection fees. Two waterside sites have first-come, first-served picnic tables, and a group picnic area can be reserved.

Fishing at Calero is catch and release. Mercury has built up in the reservoir to levels that make the fish unsafe to eat. The nearby Almaden Valley was once a quicksilver (mercury) mining district, and mercury-bearing sediment settled in local reservoirs, where bacteria can turn it into methylmercury that collects in fish.

The back country has 18.9 miles of trails for hikers and equestrians, starting from a large staging area next to the park office with parking for cars and horse trailers. Cyclists can ride the 0.5-mile Serpentine Loop Trail, which connects to the Longwall Canyon Trail in the Open Space Authority's Cañada del Oro Open Space Preserve, and the connecting trails between the two parks are open to all users. Leashed dogs are allowed on the Bald Peaks Trail and all trails north of it.

The park is open from 8 a.m. to sunset, and trails open at sunrise. A vehicle entry fee applies year-round. The McKean Road main entrance and the Rancho San Vicente entrance have free parking and restrooms, while the boat launch entrance has paid parking.