Yellowstone Mountain removes 'offensive' name to instead honor Native Americans:  Since 1871, a mountain peak in Yellowstone National Park has worn the name Mant Doame, named after Lieutenant Gustavus Cheyney Doane. But with this name's grim history has seen it declared offensive and as of this month, the National Park Service has renamed the mountain First People's Mountain.                                     In 1870, Doane led an assault known as the Marias Massacre-against local Piegan Blackfeet Indians. 173 Native Americans died as a result. Among those dead were tribe elders, women, and children suffering from smallpox.