Greenbrier Minerals vice-president and human resources administrator Gary Groves told local news station WVNS Tuesday that Mountaineer One, Mountaineer Two and Midland Two would idle if a contract or contracts were not signed.
It has already distributed regulatory-required notices to about 100 people who will be impacted by the potential closures.
Groves told the station that the company was hopeful, but indicated that December 31 would be the final day of mining should it be unsuccessful.
The Rupert-based miner did not release any further comment on the decision.
Keep watching ILN for more on this situation as it becomes available.