BISMARCK, N.D. (AP) — The Army Corps of Engineers is recommending that the federal government negotiate a settlement with North Dakota for more than $38 million that the state spent policing protests against the Dakota Access oil pipeline.

In a letter obtained by The Associated Press, the Department of the Army is asking the Department of Justice to enter into settlement negotiations with the state “to avoid protracted and costly litigation, particularly in light of the harm that occurred in this case.”

The request comes following U.S. District Court Judge Daniel Traynor’s decision last month to deny the federal government’s motion to dismiss North Dakota’s lawsuit seeking to recover more than $38 million in damages the state claimed from the monthslong pipeline protests almost four years ago.

“I request that you consider engaging in settlement discussions with North Dakota to determine whether a reasonable resolution is within reach,” Army Under Secretary James McPherson wrote in his letter to Acting Assistant Attorney General Ethan Davis.

North Dakota Republican U.S. Sen. Kevin Cramer called the recommendation “very significant” and the right thing to do for the federal government.

“North Dakota assumed all costs including the cleanup of actions facilitated by the Corps of Engineers,” Cramer said Tuesday. The state “has one thing in mind and that is to make us whole. We don’t go away on these things like everybody else.”

The $3.8 billion pipeline has been moving oil from the Dakotas through Iowa to Illinois for more than three years. Thousands of opponents gathered in southern North Dakota in 2016 and early 2017, camping on federal land and often clashing with police. Hundreds were arrested over six months.

North Dakota Attorney General Wayne Stenehjem has long argued that the Corps allowed and sometimes encouraged protesters to illegally camp without a federal permit. The Corps has said protesters weren’t evicted due to free speech reasons.

Traynor, who is based in Bismarck, ruled last month the Corps failed to comply with its own mandatory permitting process.

“As a result, there was no limitation on the gathering and no bond available to clean up the spoiled environment that was left,” his ruling said.

Stenehjem said he had an appointment to speak with federal lawyers by telephone on Tuesday.

“We have made our demands,” Stenehjem said. “I hope they are willing to negotiate in good faith. If not, we will prepare for trial.”

Stenehjem said North Dakota has a strong case and holds the upper hand in negotiations now with the federal judge’s ruling last month.

“I wouldn’t trade legal positions with the Corps,” Stenehjem said.