PROVIDENCE, R.I. — The remains of the Wampanoag leader who forged a peaceful relationship with the Pilgrims will be reburied at his original grave site in Rhode Island.

Members of the Wampanoag Nation have spent 20 years tracking down the remains and artifacts of Massasoit Ousamequin. It was their “spiritual and cultural obligation,” said Ramona Peters, who coordinated the effort.

Ousamequin signed the first treaty with the Pilgrims after they arrived on the Mayflower, promising in 1621 in the village that became Plymouth, Massachusetts, to protect each other, according to the Wampanoags. The peace lasted for decades.

Ousamequin was buried on a hilltop in Warren overlooking Narragansett Bay. His remains and artifacts were scattered when a railroad was built through the burial site nearly two centuries after his death and archaeologists and local residents dug there.

Objects belonging to Ousamequin, which translates to “yellow feather,” became part of collections in seven museums. A private ceremony is planned for May at the gravesite.

A federal law that took effect in 1990 requires museums to transfer remains and any associated burial objects to culturally affiliated tribes. The purpose of the law, the Native American Graves Protection and Repatriation Act, was to allow for reburials consistent with tribal traditions. Peters said it has been difficult because there was resistance from some museums at first.

“Native Americans across the country appreciate Congress passing this, which makes the entire repatriation possible,” she said Friday.

Ousamequin’s artifacts include a pipe, knife, beads and arrowheads.

The Rhode Island Historical Society has repatriated about 75 items to the appropriate tribes since the law’s passage, including artifacts belong to Ousamequin. They were donated as relics in the 1800s, but collections aren’t assembled in that way today, said Kirsten Hammerstrom, director of collections.

“Grave goods are not something we dig up and accept. They belong to the tribe,” she said.

Peters is a citizen of the Mashpee Wampanoag Tribe on Cape Cod, Massachusetts.

The Wampanoags have collected hundreds of funerary objects that were removed from the burial ground on the hill and held dozens of burials for their ancestors whose graves were disturbed, Peters said.

“It is an honor and a privilege to be able to do this for our ancestors,” she said.