Nestled in a cool, foggy canyon north of the Golden Gate, Muir Woods is the world’s most famous grove of virgin redwoods (Sequoia sempervirens). These tall trees are a spectacular remnant of the vast redwood forests that once graced the slopes and valleys surrounding San Francisco Bay. Easy, flat trails loop through Muir Woods along a creek where endangered coho salmon spawn each winter.

Redwoods grow taller than any other tree species in the world. The average age of the redwoods in Muir Woods ranges from 400–800 years old, and many ancient specimens have been around for more than a millennium. The grove’s tallest tree stands more than 250 feet high.

Muir Woods is the only sizable stand of old-growth redwoods remaining in the San Francisco Bay Area (“old growth” refers to the presence of mature redwoods, seedlings, dead and fallen trees, and diverse understory plants).

Camping, picnicking, smoking, bicycles, and dogs are not allowed in Muir Woods.

VISIT MUIR WOODS: TIPS AND HIGHLIGHTS

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  The Visitor Center at the Muir Woods entrance has exhibits and an excellent selection of brochures, books, and other information on Muir Woods.
• A café and gift shop is also located near the park entrance.
• Visitors 16 years and older must pay an entrance fee. (Note: entry fees are scheduled to increase from $5 to $7 on Jan. 1, 2012).
• Escape the crowds by returning to the Visitor Center via the Hillside Trail.
• Many of the canyon floor trails are boardwalks and paved trails, making the paths wheelchair-accessible.
• Park in the Muir Woods lots (two lots, follow the signs) or along the roadside shoulder below the park. The best time to visit is weekdays, or early or late on weekend days. Summer weekends are very crowded, and parking lots fill quickly.
• A nice way to avoid parking problems is to hike in from other park areas. The 1.5-mile hike is steep and one should allow a 30–45 minutes to reach Muir Woods. A West Marin Stage bus provides weekend service to Muir Woods from May–September.

Salmon Spawning in Redwood Creek
During the winter, heavy rains break open the sandbar at Muir Beach, where the mouth of Redwood Creek—which flows through Muir Woods—empties into the sea. The surge of fresh water that is sent into the ocean tells the endangered coho salmon that it’s time to return to the stream of their birth to spawn.

You can watch the spawning rituals of the brick-red salmon from the footbridges that cross the creek at intervals among the redwoods. The biggest spawning runs happen two or three days after a big December, January, or February storm. Salmon runs have declined in recent years, and park managers are working to restore and enhance habitats in the Redwood Creek Watershed to support and encourage their renewal.

Fire
Before European settlers came to the Bay Area, fires burned through the region’s forests several times each century. In the forest, fire actually serves as a natural cleansing agent, clearing out deadwood, killing pests, fertilizing the soil, and giving new plants a chance to grow. Many fire-blackened hollows mark the tree trunks in Muir Woods.

Fog Drip
Northern California has what is known as a Mediterranean climate: wet winters and dry summers. Throughout the year, fog is an important source of moisture. A third of the total moisture available to local plants—including the towering redwoods—is produced by fog drip, a phenomenon in which fog droplets condense on the leaves of trees and coastal scrub.

The Saving of Muir Woods
Back in Gold Rush times, local forests were scoured to accommodate the burgeoning city of San Francisco. Because it was inaccessible, Muir Woods escaped the saw until 1905, when Marin County conservationist and politician William Kent bought the canyon to save these redwoods.

Muir Woods was still in danger, however. Two years later, a local water company sued to condemn the canyon floor for a reservoir. Kent sent a desperate plea for help to President Theodore Roosevelt, who in 1908 agreed to declare the canyon a national monument. At Kent’s special request, the forest was named to honor John Muir, the renowned conservationist who founded the Sierra Club.

Muir Woods National Monument—one of the last stands of old-growth coast redwoods in the world—celebrated its 100th anniversary as a National Monument in 2008.