 The Black Trail is the most challenging one. The trails are gorgeous, but you need to climb almost down through the river in the canyon and back up. And it winds itself through different ridges and different biosystems, habitats. It's basically the perimeter trail inside the entire reserve with a length of 5.3 miles. It's just an adventure every time I'm at the reserve, and I see animals and wildlife and plants every time, something that I didn't see yet.