Parking at the Buxton Trailhead has no day-use fee and saves several miles of driving to Stub Stewart State Park. Get a good warmup going up the Banks-Vernonia paved trail, then enjoy some hand-build singletrack. When you get to the end, turn around and enjoy.
This direction starts at the lower end of the MTB and ends at the Upper end. Lots of climbing in this direction and most people prefer to ride it only in the opposite direction.
Buxton trailhead is a little bit hidden, but offers a sizable gravel parking lot, vault toilet, and covered pavilion. Ride uphill (do not cross the trestle bridge) on paved BV trail for 2.2 miles. To the right is a wide dirt path that leads down to Fellings Wedge. Take a left and you'll find the bridge that crosses to the MTB-only trail.
Trail starts with a tough climb with lots of switchbacks and turns, eventually you reach the top where the forest opens up and the trail becomes more flat and flowly. There are a couple of stream crossings that are not rideable, foot crossing only.
Climb above the stream and you'll eventually find the first intersection of the trail - The Visitor Center Loop
. Keep left at all intersections and you'll arrive at the end of the MTB-only trail with a fence and kiosk. Turn around and ride back out for some very fun descending.
Banks-Vernonia State Trail is a historical logging railway that is now a recreation trail.