Not alot of people compared to the other national parks. This one is a gem. The imagery is spectacular, even surreal. Since its so far away, I recommend at least 3 days exploring the park. If you want an all day hike and are in good shape, do the South rim which is about 15 miles roundtrip. Views at the top are amazing, and you can see maybe 50-100 miles out in every direction on a clear day, overlooking vast mountainous desert expanses. For camping checkout Chisos Basin Campground. No mountain biking allowed, but you can bike on the main roads. Right outside the park is the town of Terlingua, famous for its chili cook-off. And you also have Marfa, famous for the Marfa lights. It gets really hot in the summer. Spring and fall are best times to go. Even wintertime on a sunny day is a good time.