Wait for a late fall or winter storm to clear the air, then try this viewful trek to Sierra Peak, a rounded promontory anchoring the north end of the Santa Ana Mountains in Orange and Riverside Counties. The 14.5 miles of round-trip travel to the peak is long and tedious for hikers, challenging for runners, and somewhat less challenging for mountain bikers. The out-and-back route follows well-graded fire roads throughout and the climbing is quite gradual, though you end up gaining and losing a total of 3200 feet of elevation.
Around the winter solstice, an afternoon/evening hike to and from Sierra Peak can be very rewarding. Plan to reach the peak in time to watch the sun drop into the Pacific (before 5 p.m. from early November to early January). Then stroll back down under the stars, arriving at your car before 8 p.m. Nights lit by a full or nearly full moon are best; otherwise, the glare of the city lights below makes it hard to see the ground underfoot. Don't forget extra warm clothes and a flashlight.
Geologically, this is an interesting area. About two miles up from the trailhead, you'll cross the Elsinore Fault zone, with crumbly 150-million-year-old metavolcanic rock to the southwest and colorfully banded marine sedimentary rocks half that age to the northeast. Near Sierra Peak are some nice exposures of sandstone with embedded cobbles.
To reach the trailhead, take the Lincoln Avenue exit from the Riverside Freeway (Highway 91) in Corona and drive three miles south to Chase Drive. Turn right on Chase, then turn left where Skyline Drive branches south. Pull up and park near a massive gate (probably closed) designed to keep vehicles out.
Bypass the gate, and continue up the road on your own power. After the first mile, the road swings back away and up from the mouth of Tin Mine Canyon, once a target-shooting area but now mercifully quiet. Soon, views open up of nearby Corona and more distant Riverside and San Bernardino, backed up by the towering summits of the San Gabriel and San Bernardino Mountains. In the carpetlike orange groves below, new subdivisions seem to push and leapfrog along.
Oak Flat, 4.8 miles from the gate, is marked by grassland dotted with a few oaks and a radio communications complex. At the road junction turn right (Black Star Canyon Road goes left, south) and continue along the main divide of the Santa Anas toward Sierra Peak, the antenna-bristling summit to the north. On top there's a great view of the Chino Hills and Pomona Valley to the north, the broad trough of Santa Ana Canyon to the west, and endless miles of L.A. Basin suburbia stretching toward the Pacific Ocean.
For more information, call the Cleveland National Forest, Trabuco Ranger District office in Corona: 909-736-1811.