The Castle Gate Coal Co. has laid off 86 hourly and 12 salaried employees at its underground mine due to depressed market conditions, the company has announced.

The layoffs leave 155 hourly and salaried workers at the mine.The company decided to reduce its operating level below the 1.5 million tons annual capacity and to concentrate efforts on existing customers and commitments, according to a news release.

Castle Gate has been developing and rehabilitating the mine since 1986 and recently finished installing a new unit train rapid-loadout system. The company also has signed two new agreements to supply coal to industrial users in California, the release said.