PORTLAND, Maine (AP) — The Maine Department of Education is not doing enough to enforce a decades-old law requiring students to be taught about Native American history, leading most schools to fall short, according to a study.

The study, released on Monday, which is Indigenous Peoples Day in Maine, concluded most school districts are failing to cover all required areas of Wabanaki studies.

“Teaching Wabanaki Studies is not optional. It is required by law,” Michael Kebede, policy counsel at the American Civil Liberties Union of Maine, said in a statement.

The Wabanaki Alliance, Abbe Museum and the ACLU of Maine used the state’s open records law to survey 10 districts and the state education department on their compliance with the law. The Maine Indian Tribal-State Commission also joined in the report.

The 21-year-old state law requires schools to teach Wabanaki history, economic and political systems, and culture. The Wabanaki are comprised of the Penobscot Nation, Passamaquoddy tribes at Indian Township and Pleasant Point, Houlton Band of Maliseets, and Mi’kmaq.

The study came at a time of fraught relations between the tribes and the state of Maine.

The tribes are pressing to change the Maine Indian Land Claims Settlement Act of 1980, which prevents tribes in the state from having the same rights as the other 570 federally recognized tribes.

The Maine House approved the bill that would have amended the settlement in April, but the Maine Senate never gave a final vote because of a threatened veto by Democratic Gov. Janet Mills.

The tribal frustration comes despite some successes: The state ended tribal imagery for high school mascots, changed the name of Columbus Day, and gave tribes revenue from mobile sports betting.

President Joe Biden proclaimed Monday to be Indigenous People’s Day for the second year, as states and cities rebranded the federal holiday that had long-celebrated Christopher Columbus’ sighting of what came to be known as the Americas.

But Rep. Jeffrey Evangelos, an independent from Friendship, said in an op-ed in the Portland Press Herald on Monday that Maine’s Indigenous people are still treated as “second-class citizens.”

“The relationship between the Wabanaki Nations and the state of Maine is frayed, and one way to repair that relationship is for the state to invest in proper implementation of the Wabanaki Studies Law,” said Maulian Dana, a Penobscot and president of the Wabanaki Alliance.

The state contends it’s making progress in schools.

Maine Education Commissioner Pender Makin convened a working group of tribal leaders and Wabanaki scholars in the first months of the administration, an agency spokesperson said.

Decisions on what’s taught in the classroom are made locally, and the Maine Department of Education provides resources by grade on its website that have been reviewed by tribal cultural experts and educators, spokesperson Marcus Mrowka said.

The agency recently hired an educator to lead the work of creating lessons for the state’s online lesson sharing website for teachers from kindergarten to high school, Mrowka said.

Across the country, there have been recent gains in teaching students about Native Americans, with new requirements in states such as Connecticut, North Dakota and Oregon.

Maine adopted its law in 2001, identifying material that should be taught and creating a Wabanaki Studies Commission to compile resources for teachers.

But the review revealed that one school district had no records demonstrating how it complies with the statute, and another admitted it didn’t systemically include Wabanaki studies in its curriculum.

Several school districts referred to Wabanaki people in the past tense and focused only on colonization, playing into a misconception that Wabanaki people are either invisible or a thing of the past, the report said.

The survey cited some successes in Old Town, Portland, Bangor and Lewiston, which incorporated Wabanaki people in several different study disciplines. Presque Isle brought Mi’kmaq drummers into their schools, and Houlton invited Mi’kmaq and Maliseet members to class. Calais offered a Passamaquoddy language course.

“Schools achieved the most success when they partnered with Wabanaki experts,” the report said.