On June 16, 1805, Captain Lewis, returning from his reconnoiter of the falls, rejoined Captain Clark downriver from here and found Sacagawea extremely ill. Having passed this spring earlier, Lewis suspected its medicinal water might help her and sent several men to procure water from the sulphur spring to try on the ailing woman. Within one day of drinking it, Lewis reported every rational hope of her recovery, though the medicinal value of the mineral waters remains uncertain. For thousands of years Indians valued the healthful qualities of the sulphur water, camping near its source and likely drinking and soaking in it, and in 1886 local residents also praised it in the Great Falls Tribune as a favorite resort for the sick and an effective cure for many ills.