Now that the days are shorter and the sun is low on the horizon, it's a good time to explore the open grassland areas of Marin. During the summer, the south facing slopes of northern Marin can be scorching. This time of year, the grassland ridges tend to be cool and breezy and great views prevail. The grasses are just starting to sprout new green growth and a few hardy wildflowers remain. 

We decided to do a "peak bag" to Big Rock Ridge and the high point at the towers. Big Rock Trail, built in 2003, has made this 1500-foot climb relatively easy. The machine-built trail is a wide, fairly gentle, multi-use trail. It works its way up along a canyon before breaking out into the grasslands for the final switchbacking ascent to the Big Rock Fireroad.

Big Rock Trail is part of the Bay Area Ridge Trail that will eventually circle the entire San Francisco Bay Area. The trail is mostly in Lucas Valley Open Space Preserve, but there are several private ranches that contain easements to cross along the way, including Redwood Canyon Ranch and Corbin Ranch that comes up from Ignacio. The trail also passes through an easement on George Lucas's Big Rock Ranch property, and there are views down into his Japanese-styled compound and lake along the upper section of the trail. 

Before 2003, Big Rock Ridge was a difficult destination to get to. The steep access fire roads kept people from easily climbing to this majestic ridge. Now Big Rock Trail is very popular with cyclists and hikers alike. Additionally, George Lucas granted an easement in 2002 that spans the gap between Loma Alta Open Space Preserve and Lucas Valley Road, where Big Rock Trail begins. This has increased traffic up and over Loma Alta from the Ross Valley, mostly by mountain bicyclists who have a greater trip range than hikers. Intrepid cyclists make a grand loop from San Anselmo and Fairfax out to Big Rock Ridge and back. 

This is an overview of a hike from the book "Hiking Marin: 141 Great Hikes in Marin County." Click here to go the Marin Trails website, where you can find more details about the book, which contains this hike and 140 more great hikes around Marin County.