From the parking area, walk south on Route 9W for a few hundred feet. Just beyond road signs for Routes 9W and 202, you'll see three blue blazes and three red-dot-on-white blazes on a tree adjacent to the road. These blazes mark the start of the Timp-Torne (blue) and Ramapo-Dunderberg (red-dot-on-white) trails. You'll be following the Timp-Torne Trail for the first part of the hike and returning on the Ramapo-Dunderberg Trail.

Follow the blue and red-dot-on-white blazes into the woods along a level footpath through an area of tangled vines. Soon, the trail will bear left and climb stone steps, and you'll reach a stone-arch tunnel to the left. This tunnel is a remnant of the Dunderberg Spiral Railway, the construction of which commenced in 1890. The plan was to have the rail cars pulled up the mountain on a cable incline by a stationary steam engine, with the downhill journey being made by gravity. Large sums were spent on the project, two tunnels were partially completed, and much of the line was graded, but the promoters ran out of funds, and the railway was never finished. The tunnel you see to the left was designed to allow the ascending trains to pass over the route of the descending trains.