Acknowledging that child welfare practices once removed children from tribal families — tearing apart their families and leaving them vulnerable to abuse — Maine’s Indian tribes and state officials signed an agreement Tuesday aimed at ensuring that history does not repeat itself.

Their pledge to create a formal “truth and reconciliation” process marked the start of a multiyear effort. They hope to uncover the truth about tribal experiences with the child welfare system, implement changes and promote healing among victims such as Denise Yarmal Altvater, 51.

Yarmal Altvater said she remembers the day 43 years ago when a pair of station wagons pulled up outside the Pleasant Point home in which she and five sisters were being raised by their single mother, an alcoholic.

The girls ended up in an abusive home, Yarmal Altvater said, leaving her scarred psychologically. Telling her story has helped her to find peace, she said.

“Our ultimate goal is to help others to heal from this process. To give native people a place where they can tell their story, where they’ll be believed, where they’ll start to heal,” she told The Associated Press before Tuesday’s formal ceremony on Indian Island.

The agreement was signed by Gov. Paul LePage and representatives of the Aroostook Band of Micmacs, Houlton Band of Maliseets, Penobscot Indian Nation and the Passamaquoddy tribes at Pleasant Point and Indian Township. The ceremony was held in the Penobscots’ Sockalexis Bingo Palace. Yarmal Altvater signed the pledge on behalf of the Maine Indian Tribal-State Commission.

Before the federal Indian Child Welfare Act in 1978, it was common practice for child welfare workers to remove Indian children not only from their homes, but from their tribes, tribal advocates contend. They were placed with white families, stripping children of their heritage, they said.

Maine’s placement of native children in non-native homes was 19 times the national average, said Esther Attean, a Passamaquoddy who works with the Muskie School of Public Service at the University of Southern Maine, which is facilitating the reconciliation process between Maine’s child welfare agency and the tribes.

After the federal law was enacted, Maine’s child welfare agency made improvements. But there were still problems, Attean said, and in 1999 the state reached out to the tribes. The formal process of reconciliation began in 2008 because child welfare advocates felt an invisible wall was impeding their progress, she said.

A key part of the process is delving into what actually happened to tribes and families, and coming to terms with it, officials said Tuesday. Fully understanding the past will help everyone — both those who must heal and those who need to enact reforms, officials said.

Yarmal Altvater said revealing her painful past has helped her, and she believes it will help others. She said she was sexually assaulted and left in a dark cellar as a punishment over four tortuous years while living in Old Town.

The Maine Department of Health and Human Services asked her to participate in a video in which Indians told their stories. The agency wanted to educate caseworkers about the past practices and help them understand why the new policies are in place.

Yarmal Altvater, who has returned to Point Pleasant to live, said some people have talked about reparations but that she is not interested.

“For me, it has been a real personal journey,” she said. “There isn’t any money in the world that’ll ever give me back my dignity and humanity the way going through this process has.”