Bon Tempe Lake - Lake Lagunitas Loop, Marin County: Bon Tempe Lake Trailhead, San Francisco: Marin Headlands - Mt Tamalpais - Point Reyes, California

Bon Tempe Lake - Lake Lagunitas Loop - 6.3 miles

Marin County: Bon Tempe Lake Trailhead

View of Bon Tempe Dam from the Bon Tempe Lake - Lake Lagunitas Loop

View of Bon Tempe Dam from the Bon Tempe Lake - Lake Lagunitas Loop

Round-Trip Length: 6.3 miles
Start-End Elevation: 665' - 665' (833' max elevation)
Elevation Change: 0' net elevation change (+590' total roundtrip elevation gain)
Skill Level: Easy-Moderate
Dogs Allowed: Yes
Bikes Allowed: No
Horses Allowed: Yes
Related Trails:

Bon Tempe Lake - Lake Lagunitas Loop - 6.3 Miles Round-Trip

The Marin County Watershed encompasses 5 lakes around the base of Mt Tamalpais. Multi-use trails between Bon Tempe Lake and Lake Lagunitas join to form an easy 6.3 mile figure-eight loop ideal for running, birding and fishing along their biologically diverse shores.

Trail Map | Photo Gallery

From Bon Tempe Lake Trailhead, walk through the gate and up Bon Tempe Dam Road to Bon Tempe Dam (.15 miles : 725'). Turn right and cross the dam with views of Mt Tamalpais and Alpine Lake below. 

Once across turn left onto the Bon Tempe Trail (.35 miles : 730'), which rises steadily along the shore of Bon Tempe Lake and rounds several inlets into stands of Redwoods (1.0 miles : 735').

Bear right at the Lake Lagunitas Parking area (1.75 miles : 720') and continue straight toward the lake. The trail rises moderately before leveling out near the shore of Lake Lagunitas. Bear left at an unnamed trail split (2.15 miles : 815') and continue around the lake. 

The trail undulates around Lake Lagunitas for the next 1.5 miles to its dam (3.60 miles : 795') and back down to the parking area. Cross the parking lot to pick up the Alex Froman Trail (4.0 miles : 725'), which heads back toward Bon Tempe Lake.

Anticipate several unnamed trail splits - the most direct route hugs the Bon Tempe shore. Enjoy good views, diverse wildlife and fast travel for the next 1.5 miles around the lake.

At 5.4 miles make a left onto the Sunnyside Trail, which parallels the north shore of Bon Tempe Lake all the way to Bon Tempe Dam. Retrace your steps across the dam back to the trailhead to complete the loop (6.3 miles : 665').

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Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N37 57.547 W122 36.590 — 0.0 miles: Bon Tempe Lake Trailhead - 665'
  • N37 57.444 W122 36.586 — 0.15 miles: Bon Tempe Dam - bear right onto Shadyside Trail - 725'
  • N37 57.299 W122 36.739 — 0.35 miles: Turn left after dam onto Bon Tempe Trail - 730'
  • N37 56.952 W122 36.357 — 1.00 miles: Hiking through mixed forest, redwood stands - 735'
  • N37 56.972 W122 35.904 — 1.75 miles: Lagunitas Parking Lot, bear right on trail - 720'
  • N37 56.759 W122 35.815 — 2.15 miles: Bear left towards Lake Lagunitas - 815'
  • N37 56.625 W122 35.728 — 2.50 miles: Circling Lake Lagunitas - 820'
  • N37 56.737 W122 35.512 — 3.50 miles: Continuing lakeside along Lake Lagunitas - 815'
  • N37 56.855 W122 35.782 — 3.60 miles: Cross Lake Lagunitas Dam down to parking lot - 795'
  • N37 57.039 W122 35.974 — 4.00 miles: Hop on Alex Froman Trail to Bon Tempe Lake - 725'
  • N37 57.137 W122 36.246 — 4.50 miles: Walking lakeside along Bon Tempe Reservoir - 705'
  • N37 57.310 W122 36.162 — 5.00 miles: Continue lakeside along Bon Tempe Reservoir - 715'
  • N37 57.423 W122 35.966 — 5.40 miles: Turn left onto Sunnyside Trail - 725'
  • N37 57.441 W122 36.432 — 6.00 miles: Stay left along shoreline - 730'

Worth Noting

  • The rule of the Bon Tempe - Lagunitas Loop is "When in doubt, stay close to the shore". There are many trail splits, named and unnamed - so staying near the shore ensures the most direct and efficient route.
  • This is a great birding area - bring binoculars and catch sight of herons, cormorants and egrets as well as hawks and falcons.
  • This is a heavily patrolled area - keep your dog on leash and your bike on designated trails or face likely fines from rangers.

Camping and Backpacking Information

This is a day use only area - camping is not permitted.

Fishing Information

A valid California Fishing license is required for anyone 16 years or older. See this link for detailed fishing and safe eating guidelines

Fish Viewing

Each year, beginning in November, endangered coho salmon return to Lagunitas Creek from the ocean to spawn, or lay eggs. Threatened steelhead trout return to spawn starting in late December. The adult spawning runs coincide with the rainy season and continue for three to four months, sometimes longer. Lagunitas Creek is considered the home of one of the healthiest salmon populations in central California.

Leo T. Cronin Fish Viewing Area

The Leo T. Cronin Fish Viewing Area, located along Lagunitas Creek in West Marin, is one of the San Francisco Bay Area’s most popular fish viewing areas. It is open to the public daily sunrise to sunset. The best time to see spawning fish is mid November through February.

The area is named after Leo T. Cronin, a member of the MMWD Board of Directors from 1991 until 1994. He was a leader in the movement to maintain and restore the fisheries of California and, in particular, Lagunitas Creek. He served as regional vice president of Trout Unlimited, was named Conservationist of the Year in 1979, and received the Distinguished Service Award in 1993.The fish viewing area was opened to the public and dedicated to Mr. Cronin in 1995 in his memory.

Fish Viewing Rules

When visiting the site, please remain behind the fence, minimize noise, and avoid sudden movements so that salmon may spawn here undisturbed. Catching or disturbing the fish during spawning season is prohibited by law. Dogs on leash are allowed on roads and trails but not in the creek. Parking is limited to one hour during fish viewing season.

Rules and Regulations

  • This is a fee area - $8.00 per car and credit cards are accepted. Proof of payment receipts from the Entrance Kiosk must be kept on the dashboard.
  • Bikers: There is a 15 MPH overall speed limit - and you must slow down to 5 MPH when passing hikers or other visitors. You are allowed only on designated trails and will be ticketed if found elsewhere.
  • Dogs are permitted but must be kept on leach at all times. Dogs are not allowed in the water.
  • There is no swimming or boating in these protected reservoirs.

Directions to Trailhead

From Highway 101, take the San Anselmo / Sir Francis Drake Blvd Exit and drive west on Sir Francis Drake Blvd for 6.0 miles to the town of Fairfax. Upon entering Fairfax, turn left on Pacheo Avenue then an immediate right onto Broadway. After one block, turn left onto Bolinas Road (sometimes called Bolinas-Fairfax Road).

Take Bolinas Road for 1.5 miles then bear left onto Sky Oaks Road and drive for .4 miles to the Ranger Station / Entrance Kiosk. Pay the $8 entrance fee (credit card accepted) then drive for another .3 miles to a clear fork in the road.

Bear right at the fork then drive .6 miles on the gravel road to another fork in the road. Bear left at this fork and shortly thereafter, you will see the Bon Tempe Lake Trailhead and parking area on your left.

Contact Information

Mt Tamalpais State Park
801 Panoramic Highway
Mill Valley, CA 94941

Marin Municipal Water District
220 Nellen Avenue
Corte Madera, CA 94925-1169

Trip Reports

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