After passing the Model Airplane Field on Montour Trail
Ext., you'll climb a short hill and see a trailhead dropping to the right down the hill. Follow this all the way to the bottom and make a left onto the gravel road.
Immediately after crossing the stream, make a right to climb to the top of the ridge. At the top, the trail is a combination of singletrack and doubletrack. Continue south until it drops you back out on Montour Trail