BILLINGS, Mont. (AP) — The U.S. Fish and Wildlife Service has collected samples from fish in the Yellowstone River as part of a process to determine if the fishery was damaged by last year's oil spill and if Exxon Mobil Corp. should pay for restoration work.

Workers captured trout and suckers Wednesday downstream of Laurel where the company's pipeline beneath the river broke last July resulting in an estimated 63,000 gallons of oil entering the river. Less than 1 percent was recovered.

The Billings Gazette reports the work is part of the Natural Resources Damage Assessment overseen by the state Department of Justice.

The state is looking for evidence the fishery has been damaged, and if so will urge Exxon to pay for restoration work.