(CNN) For decades, the remains of thousands of Native Americans have been resting at a university in Tennessee. But this spring, they will finally go home.

Archaeologists unearthed more than 2,000 Arikara and Mandan ancestral remains in South Dakota during the mid-20th century as part of the Missouri River Basin Survey, according to a November Federal Register report. The goal of the survey was to preserve objects that would otherwise be destroyed by an upcoming construction project.

Pete Coffey's ancestors were among those whose remains were recovered. He believes that these Arikara and Mandan remains are more than just items of historical significance.

"To native people, the spirits are very real," said Coffey, the director of the Tribal Historic Preservation Office for the Mandan, Hidatsa and Arikara Nation. "These are all elders, they have been disturbed and they need to be put back into the earth as soon as possible."

Once spring comes and the ground thaws, it will be time for their spirits to be laid to rest with their tribe, who now lives in North Dakota, he said.

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