Lake Bon Tempe

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Lake Bon Tempe - Fairfax

Head to Fairfax for a moderate four-mile loop that gives you a chance to see birds on Lake Bon Tempe and views from Rocky Ridge while hiking through the chaparral.

Start from the parking lot below the Bon Tempe Dam and walk up to the dam. There are almost always double-crested cormorants there. The solid black ones with yellow-orange bills and “chins” under are adults, while the ones with a pale neck and breast are juveniles. I have seen bald eagles from this dam more often than any other spot in Marin. After an absence of many decades, bald eagles returned to nest in Marin in 2008. Benjamin Franklin did not approve of the choice of the bald eagle as our national symbol because it likes to steal fish from other birds. When I led a class on this hike, we witnessed a dramatic sight — an osprey chasing a bald eagle that had tried to steal its fish. On another recent hike I heard distressed crows raising a ruckus, and saw a bald eagle in a tree eating a member of their flock.

Turn right after crossing the dam, and turn left on Rocky Ridge Road. This heads uphill, fairly steeply at first, gaining about 500 feet in 1.8 miles. Views east to Pilot Knob, the Bay and Mount Diablo get better as you climb. When I did this hike at the end of January I saw dozens of orange and black California tortoiseshell butterflies that had just emerged from hibernation. They will lay their eggs on the California wild lilac, which the emerging caterpillars feast on, sometimes defoliating the bush.

After passing Stocking Trail on your right, you begin to move off the serpentine and out of the chaparral. Look for the new bright green leaves of star lilies. Turn left on the Lagunitas-Rock Spring Fire Road and head downhill. At the junction with the Berry Trail some hound’s tongue was in bud and will probably be in bloom by the time this goes to print. Descending the Berry Trail I noticed the new leaves of wavy-leaf soaproot. This hearty plant often grows right in the trail. It lives up to the “wavy-leaf” part of its name, so you won’t confuse it with iris or star lily leaves. Miwoks used this plant for many things in addition to using the root for soap. It could also be used to make glue. The mashed bulbs could be thrown in a stream where the organic compounds called saponins interfered with fishes’ uptake of oxygen, making them easy to catch. The fibrous covering of the bulb was used to make brushes to brush ground seeds or acorns out of a grinding rock. The tips of the new leaves were eaten as salad greens.


Berry Trail descends somewhat steeply to Shadyside Trail where you turn left. Look for male and female common mergansers on the lake. These diving ducks have bright red bills. The males have white sides and breast and a green head which may look black if the light isn’t hitting it. Females have a rusty brown head that looks like they are having a “bad feather day.”

Fetid adder’s tongue is already blooming along Shadyside Trail. This delicate brown lily with spotted leaves is often mistaken for an orchid.

From Highway 101 take the Sir Francis Drake Boulevard exit. When you get to Fairfax, turn left at Pacheco Avenue, then right on Broadway. Turn left onto Bolinas Road and continue approximately 1½ miles. Turn left on Sky Oaks Road when you see a wooden sign on your left saying “Lake Lagunitas.” Turn left on the dirt road to the Bon Tempe Reservoir, about half a mile past the entrance gate. Dogs on leash permitted.

Wendy Dreskin has led the College of Marin nature/hiking class Meandering in Marin since 1998, and teaches other nature classes for adults and children. To contact her, go to