After paying a small entrance fee, head northwest on a level, paved path, passing an information board with history of the park and of the redwood-conservation movement. This path is commonly called the Main Trail, but it is also the continuation of the Bootjack Trail from Mt. Tamalpais State Park.

      About 100 feet from the trailhead, you pass a path, right, to the gift shop and the cafe, which are open 9 A.M. to 5 P.M. Redwood Creek, which gathers water from several tributaries cascading down the south side of Mt. Tamalpais, is on your left.

      Approaching Bridge 1, you get your first look at the giant coast redwoods that fill the valley, making this such a special place. Beyond Bridge 1, you stay on the east side of Redwood Creek. Rest benches here and there invite you to sit and contemplate the sights and sounds of this ancient forest, which, on weekends, may be full of visitors.

      A junction with the Ocean View Trail, right, serves as a meeting place for ranger-led walks; times for these are posted near the entrance station. Continuing straight, you enter a realm dominated by giants. Dense stands of redwoods create a shady environment suited to only certain other types of plants, and the thick carpet of needles and twigs deposited each winter, called duff, makes it hard for seeds to sprout.

      When you reach Bridge 2, where a vending machine has maps for sale, look across the creek: there stands the monument’s tallest tree — 253 feet — and, at 13 feet in diameter, its most stout. Stay on the east side of the creek. Beyond the bridge, the canyon holding Redwood Creek narrows, with steep hillsides rising both left and right.

      Passing Bridge 3, left, you enter Cathedral Grove, where the path divides around this fantastic stand of trees. You come to the Fern Creek Trail, where you turn right, leave the paved path, and get on a dirt trail. With Fern Creek in a narrow canyon on your left, you enter Mt. Tamalpais State Park. A wooden bridge takes you across Fern Creek, and then the trail bends right, passing a set of steps leading down to the creek. The next bridge takes you back across Fern Creek, and a third, parallel to the creek, crosses a gully which holds a seasonal stream.

      Soon the trail makes a sharp right-hand switchback and begins to climb. Where the Fern Creek Trail continues straight across a plank bridge nailed to a fallen redwood, at about 1 mile, you go straight on the Lost Trail. After a set of wooden steps, the trail bends left, still rising on a moderate grade. A dramatic change in vegetation marks a transition out of the redwood forest and into the realm of Douglas-fir, canyon oak, and fragrant California bay.

      After following a winding course, the trail meets the Ocean View Trail at a T-junction. Turn left and continue climbing on a long, steady grade that changes from gentle to moderate. From the base of a large boulder, a rough path leads uphill and right, but your route curves left, then straightens. After a rising traverse across a steep, open hillside that drops left, you come to a four-way junction.