Miles and Miles of narrow singletrack with Rocks everywhere. Lots of climbing and descent options on so many trails. The loop I listed follows the outside of the park (easier trails, MOSTLY). This place is a technical riding training area. You'll get twice the workout in half the distance, guaranteed.
Pay attention to the trail markers. Most areas have very technical sections with low hanging tree limbs EVERYWHERE. At 6'3 I was constantly surprised by just how low I had to duck (OUCH).
Starting from the parking area, it's a nice easy ride up Rockville Trail
(basically fire-road). Continue along the road until you reach the paved road. Take a left and within a couple hundred yards you'll see a gated area off to the left leading to Lower Tilley Trail
Although this trail starts off moderate, it rapidly gets very narrow and has some very technical areas. I ran the loop clockwise for this ride, but in general, I would recommend instead to run this loop counter-clockwise. It can be done both ways but the counter-clockwise direction is a bit easier and is the most commonly used route. After coming back to your start point, exit the gated area and turn left heading along Lower Lake Loop
Trail. You'll pass through a mini rock garden (marked) and continue to Bay Area Ridge Trail
The BART is basically just a loop around a small lake in the center of the park but there are more than a dozen different trails marked BART. Follow along this trail until you see a steep fire-road climb to your left. Head up this climb until you reach Green Valley Trail
. Head down this rocky steep descent until it changes into Black Oak Trail
. You'll begin a gradual climb eventually the trail will come to a gate that you must pass before reaching Middle Mystic Trail
. Continue along this trail which has a nice downhill with a switchback and several VERY LOW HANGING TREE LIMBS...., Jockey Junction a short connector will put you on Outside Loop Trail
(If you choose Unknown Trail
it is a Black Diamond much more technical trail).
Along the outside loop trail is a short section called Cliff View, nice view of the valley from here. Outside Loop Trail
will then connect with Cave Trail (I dismounted for a short extremely technical downhill through a rock gully to Lake Front Trail
. Follow this trail back to the center lake, along this trail you'll find several technical sections along with a couple switchbacks, you'll then connect with the the Bay Area Ridge Trail
(BART) again head uphill along a steep fire-road to a nice technical downhill across some granite slabs on the Quarry Trail
. The trail is all downhill back to the Parking Area.
You can run this park in literally hundreds of different combinations but whatever way you decide to go expect a lot of climbing with tons of technical riding and some very nice (and fast) downhills. Almost nothing in this park is flat, Enjoy!