This part of the Centennial Trail begins at the Iron Creek Horse Camp Trailhead in Custer State Park and travels through a dense ponderosa pine forest in the rolling Black Hills. You'll definitely enjoy the many creek crossings that this trail has to offer, along with the cliffs, canyons and bends . Be cautious of a few strenuous climbing spots, and be sure to pack plenty of water and supplies. Most people will do this route as a one-way day trip with necessary vehicle arrangements, but it can also be done as an out and back. Custer State Park requires a park entrance license for each vehicle, and the Black Elk Wilderness requires free registration.