Crystal Hot Springs

Crystal Hot Springs sits along the Bear River near Honeyville in Box Elder County, Utah, on a site originally developed as Madsen Hot Springs in 1901. The resort's hot spring emerges from roughly 8,000 feet down at 120-134°F (49-57°C), with water estimated at about 22,000 years old, and the operators cite a mineral concentration of about 46,000 mg/L — by their account the highest of any hot spring in the world, compared with roughly 1,000 mg/L for an average hot spring, rich in potassium, magnesium and calcium. A cold spring less than 50 feet away, at 65-75°F (18-24°C), forms what the resort calls one of the closest hot-and-cold spring pairs anywhere; together the two springs supply around five million gallons of water a day before flowing on to the Bear River. Both springs feed a mix of soaking pools, hot tubs and a seasonal Olympic-size swimming pool.