American Treasures: Big Bend National Park blends desert, mountains and history.

Big Bend National Park sprawls across more than 800,000 acres of western Texas. Rugged mountain peaks look out over sweeping stretches of desert. Limestone cliffs rise precipitously over the green waters of the Rio Grande, separating Texas from Mexico. Adobe ruins pay testimony to the ranches of the Old West. And, it turns out, mountain lions and black bears frequent the area, along with deer, javelina and hikers.