BILLINGS - Miners at the Absaloka Mine, about 30 miles east of Hardin, went on strike at 12:01 a.m. Saturday in a multi-issue dispute.
The 15,000-acre single-pit surface coal mine is owned by Westmoreland Resources Inc.
The 125 miners are members of Operating Engineers Local 400 Montana. They have been working without a contract since March 20, said George Golie, business manager for the union.
The original contract ended March 1 but was extended to March 20 before it expired, Golie said.
"Both sides have been negotiating in good faith since then," he said.
The union received a final offer on Tuesday, Golie said, and 108 members voted on it.
"It was overwhelmingly rejected by the membership and their vote was to go on strike," he said, declining to give a specific vote count.
Officials with the mine could not be reached for comment Saturday.
The main issue, Golie said, has to do with the length of a new contract. Westmoreland is seeking a five-year pact while the union only wants a three-year contract.
The union also is seeking full retroactive pay to March 1, Golie said. There are also some work-rules issues, he said, mainly over scheduling, as well over payment of premium time for holidays and Sundays within the work week.
Golie said the two sides have agreed to go back to the negotiating table, with a federal mediator, either Wednesday or Thursday. Until then, he said, pickets will be out at the mine around the clock.
Westmoreland Resources Inc. is a subsidiary of the Westmoreland Coal Co., which is based in Colorado Springs, Colo. According to the Westmoreland Coal Co.'s Web site, it is ranked as the ninth-largest coal producer in the country.
Coal reserves at the Absaloka Mine are leased from the Crow Tribe, Web site said. The mine produces about 7 million tons of coal annually and its principal customers are located in the upper Midwest.
An April 5 Associated Press story said Westmoreland has proposed extending the surface mine's boundary onto the reservation, which would add 3,660 acres. The expansion would allow recovery of nearly 77 million tons of coal and would extend mining until about 2023.