BISMARCK, N.D. (AP) — The state of North Dakota and the federal government have filed a lawsuit over a large oil spill that contaminated the Little Missouri River and a tributary in 2016.

The federal lawsuit filed this week against Belle Fourche Pipeline seeks civil penalties and nearly $100,000 in reimbursement for the North Dakota Department of Environmental Quality’s efforts in responding to the 600,000-gallon oil spill.

The lawsuit also names Bridger Pipeline as a defendant and raises allegations related to a 2015 oil spill in eastern Montana that affected the Yellowstone River.

Both pipeline businesses are part of True Companies, based in Casper, Wyoming.