Lost Valley Campground is located near Ponca, southwest of Harrison, Arkansas. The trail is accessible year-round. The trails is 2.4 miles round trip. Best done in late fall or early spring for a more spectacular look at the water falls. Trail is very scenic, rated easy Note this area is heavily visited on the weekends. Best visited during the week if you want a little solitude. Trail ranges from crushed rock to natural services. The most scenic area of the trail is more demanding but worth it.