(From http://www.parksconservancy.org/ website) ...
People do not just visit Muir Woods. They come from around the globe to pay homage to nature in this cathedral of redwoods. The trees' ages range from 400 to 800 years, their height up to 250 feet. Flat easy trails loop through the groves. Muir Woods National Monument was established on January 9, 1908 when President Roosevelt signed legislation to protect an old-growth coast redwood forest from destruction.
In the light gaps beneath the redwood trees are red alders, California big leaf maples, tanoaks, and Douglas fir. The forest floor is covered in redwood sorrel, ferns, fungi, duff, and debris. Several bridges cross Redwood Creek, which flows through the park year-round. Wildlife residents include the endangered coho salmon fingerlings, Pacific wren, woodpeckers, owls, deer, chipmunks, skunks, river otters, and squirrels to name a few.