A 4 mile loop starting at Skyline Boulevard and descending through dense forest from 2,000 feet to McGarvey Flat at 1,380 before ascending in slightly brighter but still shaded conditions. Perfect on a warm day. This is in Huddart Park in San Mateo county, just the other side of 35 from Purisima Creek. The hyperlapse video shows the second half of the hike.
Looks like a good hike, with some reasonable elevation change.