BILLINGS, Mont. (AP) — A Denver-based oil company has pleaded guilty to violating federal law in the deaths of migratory birds in fluid pits at the company's oil and gas drilling facilities in Montana, Wyoming and Nebraska and has been fined $22,500.

The U.S. Attorney's Office in Montana said SM Energy Co. pleaded guilty Wednesday one misdemeanor count of violating the Migratory Bird Treaty Act in each state. U.S. Magistrate Carolyn Ostby also placed the company on probation for a year and ordered it to make a $7,500 payment to the National Fish and Wildlife Foundation.

The case dates back to 2005, when the U.S. Fish and Wildlife Service documented deaths of a dozen migratory birds at uncovered open fluid pits at Nance Petroleum sites in Wyoming. Nance later become an SM Energy subsidiary.

More From K2 Radio