Big Bend Hot Springs, Texas
Big Bend National Park sits along the Rio Grande in southwest Texas. There are several hot springs in the area, but the Langford Hot Springs, also known as the Boquillas Hot Springs, are the biggest and most accessible. The site is named after J.O. Langford, who came to the Rio Grande in search of a cure for his chronic illness. He eventually built a bathhouse over one of the thermal pools. The remains of this structure can still be seen today.
According to the National Park Service, the spring water, which flows out of the ground at 105 degrees F, contains calcium carbonate, calcium sulfate, sodium sulfate, sodium chloride and lithium. People who make the brief hike from the nearest parking lot to dip their feet in the water sometimes have to leave disappointed. The pools are right next to the Rio Grande, and they often get flooded and can even completely disappear when the river rises.