Donner Party, a group of 89 California-bound emigrants who suffered one of the starkest tragedies of the westward movement. Led by George Donner of Illinois, the party left the main trail at Fort Bridger (Wyoming) in the summer of 1846 to take a little-known cutoff south of the Great Salt Lake. Early snows trapped them in the Sierra Nevada mountains. Reduced to starvation, some resorted to cannibalism. Forty-two members of the party died. A memorial park near Truckee, California, marks the site of their ordeal.