Before the French explorers, the Osage people, who were historically indigenous to the region, had called it a name meaning Big Bone River, referring to the fossils of mastodons and other ancient creatures which they found along its eroding banks.
Prior to European exploration, the Osage people, native inhabitants of the area, named the river "Big Bone River" due to the presence of mastodon and other prehistoric animal fossils discovered along its banks as it eroded.