The sculpture to the left is located at the trail head leading to Seminole Canyon and the most accessible pictographs located at the Fate Bell Shelter All sites are only available by guided tour. If you show up and there are no scheduled tours, other than a small museum, there is not much to see or do.
Some pictograph location are only accessible by scheduled boat tour. When we were last there (10/2000) the water in Lake Amistad was so low there were no tours of the boat accessible caves. I recommend a early Fall or early Spring visit. Temperatures in the Canyon can be brutal.
The day we hiked Seminole Canyon, water was rushing down the normally dry canyon to Lake Amistad. This was result of much need torrential rains the day before. The trail on this day was a little slick but not difficult.
The park is primarily a historical park but it does have 31 campsites, 23 with water and electricity and 8 with water only.
Many campers use this as a stopover from Big Bend to the east part of Texas. There are good views of the most rugged country in North America. For more information visit the park web site: