Seven tribes are asking the University of Alabama to return 5,892 human remains and the artifacts buried with them at Moundville, an archaeological park in Alabama and a major center of Native American culture from 1020 to 1650.

“The evidence presented in this claim establishes beyond any reasonable doubt that the Muskogean-speaking Tribes are culturally affiliated with the Moundville archaeological site,” reads the claim sent to the university earlier this year. “Moundville is at least as closely affiliated with the Muskogean-speaking Tribes as Plymouth Colony is to the United States.”

The Native American Graves Protection and Repatriation Act requires federally funded institutions to document remains and return them to tribes. That can be more complicated with remains that predate modern tribes, said Kathy Fine-Dare, an expert on the Native American Graves Protection and Repatriation Act.

The Moundville claim was filed by the Choctaw Nation of Oklahoma, the Chickasaw Nation, the Coushatta Tribe of Louisiana, Muscogee (Creek) Nation, Alabama-Quassarte Tribal Town, Seminole Nation of Oklahoma and the Seminole Tribe of Florida.

All seven tribes said they share a common ancestry with the inhabitants of Moundville that has been passed down through language, oral history and shared traditions in architecture and craftmanship. These tribes say they are descended from Mississippian culture known for its mound building.

The University of Alabama has returned remains to tribes in the past. The current claim remains under review.

“At this time, the University is still evaluating the claim and looks forward to working with the Tribes on this matter,” said Matthew Gage, director of the Office of Archaeological Research at the University of Alabama.

In the past, archaeologists have said it’s difficult to link inhabitants of Moundville to more modern tribes that were forced out of Alabama in the 1830s.

“Sometimes tribes don’t agree with each other, but it’s more often than not tribal people and their allies fighting with institutions in terms of the authority over the designation of who gets to say what is culturally identifiable or not,” Fine-Dare said.

The federal act passed in 1990 after tribes and their supporters discovered that museums, universities and collectors held hundreds of thousands of remains and objects from Native American burial sites, said Fine-Dare, an expert on the Native American Graves Protection and Repatriation Act.

More than 30 years after the passage of the federal law, more than half of the remains in the U.S. that have been inventoried have not been claimed because they have been designated as culturally unidentifiable — with no direct link to federally recognized tribes, Fine-Dare said. Efforts are being made to revise the law to make it easier for tribes to claim some of these bones.

Institutions aren’t allowed to determine which remains belong to certain tribes, Fine-Dare said. They must consult with tribal nations to determine where remains should be sent. Tribes making claims can use several different types of evidence, such as similarities in pottery style or Native language place names to establish a link to older remains.

“It’s a scandal,” Fine-Dare said. “And some of the most prestigious institutions have said ‘no,’ and they’ve leaned heavily on the lines of evidence that are only biological or only archaeological and ignored the other seven or eight. And they could do that in silence or in secret.”

Present-day tribes have received remains from other universities, including Indiana University, which had 700 remains from another Mississippian settlement at Angel Mounds.

In Alabama, the Choctaw Nation ceded the territory that contains Moundville to the United States in 1816, according to the claim. Most Choctaw tribes had moved west into Mississippi by then. Conflict and disease that arrived with European explorers forced many tribes to relocate as settlers claimed land for farming.

According to documents obtained by Al.com from the University of Alabama, tribes have been trying to make claims on Moundville remains since April 2018. The joint claim filed on June 11 contains more than 100 pages of evidence and supporting documents. It said the last inhabitants of Moundville left at around the same time the colonists arrived at Plymouth Rock.

Archaeologists have been studying artifacts at Moundville for more than 100 years. The archaeological park opened in 1939 and researchers have unearthed tens of thousands of artifacts at the site.

In 1980, more than 260 items were stolen from the Erskine Ramsay Archaeological Repository at Moundville. Supporters have raised more than $30,000 as a reward for information about the whereabouts of those stolen artifacts. In 2018, three pots were returned by an anonymous source.

Fine-Dare said the federal government has not provided any funding to help institutions inventory or return Native American remains. Some institutions with fewer resources may have struggled to start the process. But she said increased attention to the law has improved compliance in the South and around the country.