Coal Mine Ridge isn't really a park; as part of the Portola Valley Town Trails, the trails are on privately-owned property that's open to the public. Nonetheless, it has one of the best trail systems in the area.
Coal Mine Ridge is easy to get to, but it feels surprisingly peaceful and remote, much more so than the parks on Skyline Ridge. Like its neighbor, Windy Hill Open Space Preserve, it's free of traffic noise, which is unusual for a suburban park. Coal Mine Ridge is almost entirely wooded with attractive, bright forest that doesn't get monotonous: nice views of the wooded hills to the west and the towns to the east, plus some open meadows on the ridgetop, ensure that there's enough scenery to keep your hike interesting. Coal Mine Ridge is also a lot smaller than the neighboring open space preserves so loop hikes here tend to be shorter.
The trails are very well maintained. The ridge is usually cool and is hikable year-round.
The best trails are the ones on top of the ridge, although the Blue Oak Trail is also particularly nice. The featured hike ascends the west side of the ridge on the Toyon Trail and returns along the ridgetop on the Old Spanish Trail.
Start at the little parking area on Alpine Road. The dirt pullout often fills up, but there's usually parking a little down the street.
The Toyon Trail climbs gently but constantly through typical Peninsula tanoak and bay woodland with a dense understory. The trail is cut into the side of a hill, and through the woods are brief glimpses of the high green ridge to your right. There's almost no visible development, partly because Windy Hill OSP is directly across the canyon, and although Alpine Road runs in the bottom of the valley, there's usually no traffic noise. In the summer, fog often cascades down the slope, providing a beautiful and dramatic backdrop for the hike.
Following the second intersection, the trail gets a little steeper before descending to an intersection with the Lake Trail. Climb the Lake Trail, past a little pond, to the Old Spanish Trail.
After a short climb, the Old Spanish Trail has a continuous, gentle descent all the way back to the trailhead, making the return trip easy. At its highest point, a short spur trail leads to a bench with a view over the foothills (increasingly obscured by trees), a nice place to stop for lunch. Further along, a huge oak stands next to a trail intersection. The woods are more open along this trail and for a stretch the trail breaks out into open meadow; at one point there's a nice view along the Peninsula to San Francisco.
The trail crosses a dirt road and descends to Alpine Road under a canopy of stately trees.
© 2010, 2012, 2017 David Baselt