Location: Lucas Valley Open Space Preserve
Big Rock Trail in Lucas Valley is one of my favorite trails in Marin for mountain biking. Tucked away from all the hustle and bustle of some of the more popular trails in Marin. It has some great views, being the second highest point in Marin. There are a few different options depending on what kind of ride you’re up for. This is my quick hit ride when I just have an hour for a quick ride. Starting at the actual “Big Rock” on Lucas Valley Road it climbs to 1895 ft. It can also be accessed from either Luiz, Queenstone or Chicken Shack fireroads, all of which offer some fairly difficult ascents. Luiz is a soul crusher so be prepared!
If your feeling particularly heroic start at Luiz and add on the climb up Loma Alta starting at the end of the Big Rock Trail. Just hop across Lucas Valley Road and start your acsent. From the top of Loma Alta drop into the 680 trail which coonects to the Terra Linda Fire Road (hang a left here) and spits you out at Lucas Valley Road again and a short, flat ride back to your starting point. During the summer bring extra water for this route!