Muir Woods National Monument is located in Marin County, California, just 17 miles north of San Francisco. Although only 554 acres in size, the park receives nearly 1 million visitors a year. The park was established in 1908 to protect one of the last stands of old-growth redwood trees (Sequoia sempervirens) in the Bay Area. The age of trees within the park range up to 800 years and fall within a mosaic of redwood, Douglas-fir, hardwood, scrub, and grassland vegetation types. Within this fragment of old-growth habitat live several federally threatened and endangered species including northern spotted owls, coho salmon, California red-legged frogs, and steelhead trout.
Major natural resource issues for the park include hydrologic system disturbance, encroachment of invasive species, climate change, and visitor impact.