Santa Elena Canyon (if the river isn't flooded, cross and hike into the canyon.) Sunset at the Chisos Mountain Lodge. Hike the Burro Mesa Pouroff Trail and the Rio Grande Village nature trail. Drive the Maxwell Scenic Drive. If you are in good shape, hike out from the Chisos Lodge to the Window for a stunning view over the desert.
Several of the trails are easy, and handicap-accessible. Others are very challenging. See the official park website for details. No matter the time of year, always have plenty of water with you, and gallon jugs in your vehicle. The desert is merciless.
This is a wonderful park that's impossible to see in one day but if that's all you have, go for it anyway! almost 6 years ago