Operations at the Castle Gate Mine have been indefinitely suspended because of hazardous mining conditions, forcing the company to lay off nearly 200 employees on June 5.

Mining operations were halted March 22 after a citation was issued by the federal Mine Safety and Health Administration for hazardous coal and rock bursts along the face of the mine, a company official said."For the past several months Castle Gate Mine has experienced unusual geologic conditions. These conditions have resulted in a number of unpredictable coal and rock bursts at the face. These bursts currently present an uncontrollable and unstable mining environment for our employees," said Thomas M. Blangiardo, president and chief operation officer of the Castle Gate Coal Co.

The Indianapolis-based firm, a subsidiary of AMAX Coal Industries Inc., said the company on Monday will resume work involving coal preparation, maintenance and other related activities.

But on June 5, about 156 hourly and 41 salaried employees will be laid off indefinitely, with only 17 employees remaining on duty after that.

"We have evaluated and attempted various methods for `de-stressing' the coal to overcome this problem and have retained outside consultants to assist us in this process," Blangiardo said.

However, he said it so far had been impossible to solve the problem.

"We plan to continue evaluating geologic conditions and mining techniques in the hope of resuming mining operations at Castle Gate in the future," he said.

Castle Gate began operating the mine in 1986 and produced 544,000 tons of coal last year. The mine is located in Hard Scrabble Canyon just north of Helper.