Mountain Meadows massacre: Mormon settlers slaughter most members of a peaceful emigrant wagon train.

The Mountain Meadows Massacre was a series of attacks during the Utah War that resulted in the mass murder of at least 120 members of the Baker–Fancher wagon train. The massacre occurred in the southern Utah Territory at Mountain Meadows, and was perpetrated by settlers from the Church of Jesus Christ of Latter-day Saints involved with the Utah Territorial Militia who recruited and were aided by some Southern Paiute Native Americans. The wagon train, made up mostly of immigrant families from Arkansas, was bound for California, traveling on the Old Spanish Trail that passed through the Territory.