The 486-sq-mile Big Bend Ranch State Park sprawls across the desert between Lajitas and Presidio, reaching north from the Rio Grande into some of the wildest country in North America. As massive as it is, this former ranch is one of the best-kept secrets in Big Bend country. It's full of notable features, most prominently the Solitario, a geological formation that sprang up 36 million years ago in a volcanic explosion. The resulting caldera measures 8 miles east to west and 9 miles north to south.
The scenic River Road ribbons across the park beside the Rio Grande on FM 170. Short hiking trails between FM 170 and the river work well for day-trippers who want to stretch their legs and explore a bit of the striking scenery. Rugged hiking and mountain-biking trails crisscross the backcountry.