Hiking around Bon Tempe Lake and Lake Lagunitas in Marin

Marin's vibrant green landscapes come close to Granny Smith slopes in the spring and the hills around Mount Tamalpais resemble waves of green tea slushies. Yes, Marin sure is green and spring is prime time for admiring its shades while still tender before the summer turns the hills to yellow. In other words, it's time to hike! Come March, days get sunnier, warmer and longer and a hike is in order. 

There are two reasons you may want to hike around Bon Tempe Lake and/or Lake Lagunitas this weekend: the trail is flat-ish and the hike is only 3.8 miles with a possibility for a 3-mile extension mid-way if you're feeling peppy. That's an easy day out under the sun and you can enjoy coffee from Fairfax's downtown Coffee Roastery or lavender vanilla ice cream at the Fairfax Scoop on the way out.

One of many lakes around Mount Tamalpais, Bon Tempe is part of the Mt. Tamalpais Watershed. The reservoirs you will drive or walk by provide 75% of the domestic water consumption in Marin, the remaining 25% coming from the Russian River. Hence the no-swimming/camping/boating rule. However there are plenty of other opportunities to enjoy these lakes, the two top ones being hiking and fishing.

Minutes from Fairfax, Bon Tempe Lake is a local fishing mecca and if fish is on your mind, plan to get there at daybreak to catch one of those trouts. If hiking sounds more like your kind of day, mid-morning will do and all you need is to follow these directions. After you reach the Sky Oaks headquarters (directions at the end), follow a sign for Bon Tempe Lake 0.4 mile after the entrance kiosk. The trailhead is on your left at the parking lot on the dirt road. Park there.

We started the hike at noon with a group of roughly 50 hikers and ended at the same spot at 5.30 pm, 7 miles and a Mediterranean food break later. However you can cut this hike at 3.8 miles by going around Bon Tempe Lake only.

From Bon Tempe Lake to Lake Lagunitas

After the gate, follow the trail up to your right and enjoy the views of Bon Tempe Lake as you go over the hill. That's 140 acres of blue waters surrounded by redwoods, madrones and ferns with the occasional osprey soaring overhead. Nice, right?

Take Sunnyside trail immediately to your left. This wide dirt trail follows the lake all around and you will pass many a hopeful fisherman or woman or child staring at their fishing rods in silent anticipation. Note that the trail is dog-friendly and you will also probably see a few dogs too (or bring your own Mutt for a healthy stroll). The trail is well managed and unless it's been raining lately, sports shoes are fine (hiking shoes are recommended for the Lake Lagunitas extension).

At the north-eastern shore you get to the paved Sky Oaks Road. Cross the road and continue on Oaks Trail. As the name indicates, the trail is lined with oaks stooping low. If you want to get back to the lake shores, make a right on Pine Point Trail after 0.2 mile, otherwise keep going straight. Eventually Pine Point Trail merges with Oaks Trail again and you'll reach a large parking lot at the western tip of Lake Lagunitas.

If the kids are already slowing down, skip the Lake Lagunitas portion and come back around Bon Tempe Lake on Shadyside Trail. Otherwise, you're in for a treat with great views of both lakes from a top picnic spot.

From Lake Lagunitas parking lot to Pilot Knob
At the Lake Lagunitas parking lot, look for the fishing sign and follow the paved Lake view Road. This section is moderate including some climbing but the change of pace is well worth the effort. In the spring you will see Douglas Iris as well as Forget Me Not splashing spots of blue and purple along the trail. Roughly 0.1 mile in, turn left on Pilot Knob Trail.

You will be deep in oak and madrone underbrush, shaded almost all the way to your picnic spot. The trail will go through meadows before returning under the shade of trees and so forth during 0.5 mile until you reach a trail junction on the right to Pilot Knob.

Go right and pace yourself because this hike's climb is concentrated on this tiny portion. Gradually you will climb first on dirt then on wooden steps until you reach a bald hill with a lonely oak tree. This is it!

At your feet are is the V-shaped Lake Lagunitas, on the right the blue waters of Bon Tempe Lake and all around, unobstructed views of the eastern side of Mt Tamalpais where a fire lookout can be seen on the ridge. This is a great spot to just sit down and relax. Get your picnic out and enjoy. Little ones will enjoy climbing in the tree's lowest branches. If they climb high enough, they will even find a heart-shaped scar on one of the tree's branches. When you're ready to get going again, know that the hardest part is over and the rest is a breeze.

From Pilot Knob to Lake Lagunitas picnic area, south shore

Retrace your steps on Pilot Knob Trail and go downhill until the first junction where you will go right on Lake View Road. After 0.5 mile you will take a left on the wide Lagunitas Fire Road to go around Lake Lagunitas, a scenic stroll that will take you through redwood groves and shaded shores. At this point you are mostly going down with a few ups.

At Colier Creek you will cross a wooden bridge under the redwoods (unless you go for the iffy rock path in the creek) and continue right to continue along the lake's shore. The trail will get narrower and will bring you back to the Lake Lagunitas picnic area with the large parking lot after passing the dam.

Look for ducks and turtles around the dam and check out the cool spillway that connects Lake Lagunitas to Bon Tempe Lake. It looks like a giant water slide and that's indeed what it is - for spawning fish, of course. 

From Lake Lagunitas picnic area to Bon Tempe Lake and Dam, south shore

At the parking lot, walk south to get to Shadyside Trail. This narrow and winding trail will closely follow Bon Tempe Lake shores under the evergreen canopy. You will need to walk single line most of the way but you get gorgeous views of the lake all around minus the heat if it's a warm and sunny day.

After 1.4 mile you reach the dam that drops sharply into Alpine Lake down below. On your right the vast waters of Bon Tempe Lake, on your left the Swiss-like valley with Alpine Lake at the bottom.

The dam road is so wide you could easily ride a bicycle or more side to side. You've done it, congratulations. Your car is at the other end of the dam. For another cool - and steeper - spillway, check out the end of the dam and watch the water gush from Bon Tempe Lake in rough white "waves."

Now is the time to get a reward and head down to Fairfax for some well-deserved ice cream and coffee. Fairfax is cute, you may even want to lounge around until dinner time if the weather is nice. Next time, you can continue exploring the Mt. Tam Watershed and its many waterfalls (check out description on this blog next week).

Practical details:

• Hike: 3.8 miles for Bon Tempe, 7 miles for Bon Tempe and Lagunitas
• Download trail map here
• Directions to Sky Oaks/Bon Tempe here
• Restrooms: at Bon Tempe trailhead, Lake Lagunitas parking lot, Bon Tempe dam (south end)