The National Park Service's website says this about Big Bend's Lost Mine Trail:
"4.8 miles roundtripThis moderately difficult trail begins at mile marker 5 along the Basin Road. With it's accompanying trail guide (available at the trailhead), this is an excellent introduction to the plants and animals of the Chisos Mountains. The trail starts at an elevation of 5,600' and steadily climbs to the top of a 6,850' promontory overlooking Pine and Juniper Canyons. If you don't want to hike the whole way, one of Big Bend's greatest viewpoints is at the end of the first mile. Take a lunch and enjoy the sights and sounds of the High Chisos."
For more regional hiking information, visit: www.texasmountaintrail.com/hike