Out of nearly 200 people who died from murder or other homicides on the Oregon Trail in the mid-1800s, only one lies in a grave with a known location. Missourian Ephraim Brown, a leading figure on a wagon train bound for California, was killed near South Pass in 1857 in what appears to have been a bitter family dispute. Details, however—who killed him, why and how—are frustratingly sketchy.