Big Bend National Park. Here's what the park's website says about this hike:
"The South Rim
12 miles roundtrip
The South Rim is located at the extreme southern edge of the Chisos Mountains. At the rim, the desert floor lies 2,500 feet below you and vast panoramas of rugged desert and mountains beckon far into Mexico. The South Rim can be done as a strenuous day hike, but is best enjoyed on a 1-2 night backpack trip. Backcountry campsites are available with a backcountry permit. Hikers may make a great loop by taking the Pinnacles Trail up and the Laguna Meadow Trail down, or vice versa."
Here's a link to the park's hiking page. While you're at it, take a look at our regional hiking page at www.texasmountaintrail.com/hike Enjoy the trail!