As always, check the Park website for warnings and safety information.
Much of Beach Drive in the park is closed on weekends and holidays, so the parking lot will not be accessible on these days. However, you can access the Valley Trail via the Whittier Trail just south of Sherill Drive (see map). The Whittier Trail is 0.2mi and connects to 16th St. If you do not have a car, you can take the S2 or S4 buses to the Whittier Trail.
Note all distances mentioned below are from the starting point in Parking Lot 8.
Begin at Parking Lot 8. Walk north along Beach Drive until you come to the bridge crossing Sherrill Drive. Cross the bridge, make a right, and make your way down to the path near the water. Make a left onto the path, it is called the Valley Trail. After about 0.2mi you will come to the intersection with the Whittier Trail. Continue along the Valley Trail. After about 0.5mi you will notice the Rolling Meadow Bridge on your right. Continue on the Valley Trail.
After about 0.75mi bear right onto the horse trail (dashed line on the map). Continue straight until you come to the bridge (about 0.9mi) that crosses Beach Drive. Walk up to the street and cross the bridge (there is a sidewalk). After you cross the bridge make a left on the paved trail.
The trail will eventually end. Make a right. You will be greeted by a substantial hill at this point, on your way up to Fort DeRussy. There is really nothing left of the fort except for a sign commemorating it. After Fort DeRussy you will travel a short distance and make a right on the Western Ridge Trail (green trail markers).
You will eventually pass a small fenced in field on your right. Follow signs for the Western Ridge Trail. You will cross a paved road and continue on the Western Ridge Trail until you reach Bingham Drive. Cross the road carefully and make a right. Follow the path along Bingham Drive. At the intersection with Beach, there will be a trail on your left. Take the trail back into the woods. You will make your first two rights and then cross Beach Drive (be careful, cars can speed here). Make a left and the parking lot should be visible.