An American Indian tribe in Oklahoma is pushing back against a rock-crushing company that the tribe says will soon start mining gravel out of a mountain long considered sacred by tribal members.

The Kiowa Tribe has gathered cedar and performed ceremonies on Longhorn Mountain since the tribe was relocated from the northern Plains to a reservation in southwestern Oklahoma in 1867. But the Kiowas' long-standing tradition could be in jeopardy after the tribe says some of the mountain's landowners leased water and land rights to Material Service Corp., a Cushing-based mining company.

Kiowa historian Phil Dupoint says the tribe has had a “gentlemen's agreement” with the private landowners over the years, but fears that won't be possible once the company starts mining for gravel, which the tribe believes could start by the end of the summer based on a newspaper ad seeking workers for a rock crushing plant at Longhorn Mountain.

“We've got so many people who are concerned. It's not federal land. It's not trust land. We can only go so far,” said Dupoint, who has been researching the issue with Amie Tah-Bone, director of Kiowa Tribal Museum.