Muir Woods Shuttle to Operate on Select Holidays Only
First time ever, Muir Woods Shuttle, Marin Transit Route 66 will operate on Thanksgiving weekend November 28 - December 1, Winter Solstice December 21, and day after Christmas to New Years Day, December 26 - January 1. Click for fees, schedule, & stops More »
Muir Beach Closed (not Muir Woods) July 8th to Mid-December 2013
This alert applies to Muir Beach, and not Muir Woods. Muir Beach closed July 8th to mid-December 2013 for restoration/construction. No restrooms or parking available at Muir Beach during this period. Check back for updates or call (415)561-3054. More »
Trail Work Ahead
We're taking the time to repair our trails. Please don't be surprised on the trail to find it might be closed. The Hillside Trail is open through the winter. The Ocean View Trail is closed for the winter. The Bootjack is closed at the Spur More »
Photo by Marty N. Davis
Monarch butterflies add color to the forest and magic to the air. Each fall, they arrive by the thousands to a select few locations in coastal California, completing and annual migration that is unique among insects.
In the fall, Monarch butterflies throughout North American migrate to over-wintering sites in coast California or central Mexico. This migration is unique among insects. In fact, the North American Monarch butterfly is the only insect in the world known to make the same kind of annual, back-and-forth long distance migration as birds or whales.
We begin seeing monarchs in coastal California during late August and September. They are arriving from the states and Canadian provinces west of the Rockies, and each year to the same over-wintering sites, frequently even the same trees. First they gather in "bivouac sites" for a few days to a few months (depending on the weather). Some of these temporary sites are in Fort Mason, the Marin Headlands, Tennessee Valley, Muir Beach, and Stinson Beach -- all of which are within Golden Gate National Recreation Area. As the weather gets chilly (approximately October to February) they move to the over-wintering sites. Then in spring they depart, flying north and east in search of milkweed plants on which the females lay their eggs. Successive generations produce millions of Monarchs to repopulate the western states and provinces.
Monarch butterfly migration and over-wintering behavior is classified as a "Threatened Phenomenon" by the International Union for Conservation and Natural Resources due to habitat loss or degradation.
Did You Know?
Muir Woods National Monument celebrated its 100th Anniversary on January 9, 2008. Muir Woods was the first National Monument created in an urban setting allowing people easy access. Today more than 800,000 people from all over the world come to visit each year. More...