Thermopolis: Washakie's Gift of the Smoking Waters

At the edge of the Wind River Basin in north-central Wyoming, the Big Spring surges from the earth at about one hundred twenty-eight degrees Fahrenheit, releasing roughly one point eight million gallons of mineral water every single day. The spring has been called the world's largest mineral hot spring, and while that claim has been challenged by geologists comparing it to springs in other continents, there is no doubt that it is one of the most extraordinary geothermal features in North America.

The thermal water emerges from deep within Paleozoic limestone and sandstone aquifers, recharged by rain and snowmelt from the Owl Creek Mountains. The water descends, is heated by the earth, and rises again along fault lines that create the natural pressure required to push it to the surface. As it cools in the open air, it deposits travertine, the pale calcium carbonate mineral that builds up in terraces around the spring, creating the pale terraced formations visible in what is now Hot Springs State Park.

The Eastern Shoshone and Northern Arapaho people knew these waters for generations, calling them Bah Guewana, the smoking waters, and using them for healing. In April of eighteen ninety-six, the federal government negotiated a treaty with both nations under which they agreed to transfer the spring and the surrounding land to the United States for sixty thousand dollars. Eastern Shoshone Chief Washakie and Northern Arapaho Chief Sharp Nose both signed, each with their own motivations, the Shoshone seeking cash, the Arapaho seeking cattle and rations.

But the negotiation included an extraordinary condition that Chief Washakie insisted upon. A portion of the mineral waters, he said, must remain forever free and open to the public, regardless of who owned the land. Wyoming's first state park was established here in eighteen ninety-seven, and that condition has held for more than a century. Today, the state park contains free public bathhouses where anyone can soak in the same waters that Shoshone and Arapaho families used for generations. Upon signing the treaty, Washakie said, I have given you the springs, my heart feels good. His words are carved on a stone marker at the park entrance.