The Big Rock Trail is a mild climb toward the second highest point in Marin County, a hill that tops out at 1,895 feet. Opened in 2003 as part of a donation by George Lucas, this path is now part of the Bay Area Ridge Trail. There are many routes to the peak, including the much more difficult Novato Hill Climb, which begins on the opposite side.
Finding the Big Rock trailhead is a straightforward endeavor. Simply watch for the massive boulder on the side of the road. The trail is well marked and maintained all the way to the top. Along the way you will see large fields of California poppies and scenic vistas. About half way to the top, you can look back down to see part of the Lucas Valley Ranch expansion.
Once you reach the fire road on the ridge, you can follow the path right for a continued ascent up to the radio towers on the peak. The road continues to the left as well; however, it is quickly blocked by private land. There is no easy loop back to the parking area, but if you can get a ride, there are many routes back down from the peak that lead to different areas of San Rafael and Novato.
Note that parking at the trailhead is limited during peak times.