This place is one of the reasons that I hold the East Bay Regional Park District in such high regard. Sunol Regional Wilderness is a great place to visit and hike and you can really start to feel like you're quite a ways away, even though you actually aren't. It's also one of the few places in the Bay Area that has some easily accessible and sizable waterfalls in the springtime. Sunol offers its visitors a wide range of hiking opportunities. There is the wide and relatively flat Camp Ohlone Road trail to Little Yosemite (it's very nice but I don't think it's worthy of the name), there's the narrow, twisty, and a little bit steep Indian Joe Creek Trail that criss-crosses back and forth over a small creek (I wonder how long it will be until they change the name of this trail), and there's the wide open grassy skyline views that the Cave Rocks Road trail offers. Sunol also offers some rock climbing areas along the Injun ...oops... I mean Indian Joe trail, as well as both car camping (mostly for families), and backpack camping (a bit of a way's out along the Ohlone Wilderness Trail). And as is the case for most of the East Bay's parklands, the trails are interconnected with the other nearby parks, open space areas, and watershed lands. Oh, and I guess that I should mention that the waterfalls that I referred to at the beginning of my rant are in the Little Yosemite area, naturally enough. Make sure that you get out by sundown because they lock the gates and night and you won't be able to get your car out until sunrise.
http://www.reserveamerica.com/campgroundDetails.do?subTabIndex=0&agency=eb&parkCode=sunoGetting there:
From Interstate 680 in Alameda County, exit Calaveras (exit 21a). Follow the brown "parks" signs. (If you've exited southbound, stay in the left lane of the exit ramp, turn left, drive under the freeway and then stay in the left lane through a stop sign, to remain on Calaveras.) Drive south on Calaveras about 4 miles to the junction with Geary, and turn left. Continue on Geary almost 2 miles to the park entrance kiosk, then continue past the visitor center to an unmarked dirt lot on the left.
Trailhead details:
Lots of parking inside the park in a few lots. Entrance fee (they call it a parking fee, but as you can't park on the road on the way into the park, I consider it an entrance fee) of $5 charged when kiosk is staffed. $2 dog fee. Maps available at the entrance kiosk, Visitor Center, or Interpretive Center. Note that if you plan on parking on Welch Creek Road, you must have a permit from EBRPD. Pit toilets at the edge of the parking lot. Drinking water near the Interpretive Center. There is no direct public transportation to the park. There is one designated handicapped parking space in this parking area, but Sunol's trails are not well-suited to wheelchairs.
Gas, food, and lodging:
Gas, restaurants, and stores in nearby Pleasanton and Fremont. Camping info from EBRPD: "Overnight tent camping sites at Sunol Wilderness are available on a reservable basis by calling (510) 636-1684. The fee is $12 per night for up to 10 consecutive nights, and includes the parking fee. Several group sites are available by advance reservation only. Phone (510) 636-1684 on weekdays, 9 a.m. to 4 p.m. High Valley Camp is a hike-in camp located a steep, one-mile walk from the Visitor Center. Camp Ohlone is a seven-mile hike from the park entrance. School Camp is adjacent to the Visitor Center and may be reserved through the Sunol Park office at (925) 862-2601. Group areas are available November through May. The camps and the park itself are subject to closure or fire restriction during fire season - June through October."
Distance, category, and difficulty:
This 4 mile loop hike is moderately easy, although there are a few steep stretches. Trailhead elevation is about 410 feet. The park's highest trail reaches about 2300 feet. The featured hike climbs to about 1360 feet, then descends back to the trailhead. Total elevation change is about 1000 feet.
Rules:
Most trails are multi-use. A few are open to equestrians and hikers only, and a handful are hiking only. Dogs are permitted. Park is open from 7 a.m. to dusk (the parking lot is locked at night, so be prompt returning to the trailhead).