On a freezing January morning in 1863, Union Army soldiers launched an unprovoked assault on a winter encampment of Shoshone people in present-day southeastern Idaho. By early afternoon, an estimated 250 to 500 men, women, and children lay dead in the snow.
It remains the single deadliest slaughter of Native Americans in U.S. history—surpassing the body counts of far better-known tragedies like Sand Creek (1864) and Wounded Knee (1890). Yet because it occurred at the height of the American Civil War, the attack received little national attention at the time and was largely erased from popular history for over a century.
