Ben Johnson Dipsea Trail is a 10.8 mile moderately trafficked loop trail located near Stinson Beach, California that features a river and is rated as moderate. The trail offers a number of activity options and is accessible year-round.
Park at the Stinson Beach Parking Area
Did this hike today but started up Ben Johnson and came back down Dipsea. Part of the Dipsea was detoured onto Deer Park Fire Road (looked like surveying and land reconstruction was going on). Deer Park runs parallel to Dipsea, so it was about the same length but less trail-like for that portion (more like a small access road that's bike friendly). It didn't detour for very long, and I didn't feel as though it took anything away from the hike.
Took my parents to San Fran when they came out to visit from Ohio. They wanted to see some Redwoods so we hopped over to the Golden Gate Bridge and hit up Stinson Beach as well as John Muir National Monument. We did the small loop trail that took you thru part of the Forest and up a hillside. The park was crowded but being as John Muir was such an important person in the discovery of Americas nature it was to be expected. Great views with many cool "did you know" reads.