The mine, operated by Thunder Basin Coal Company, was recognized as the safest small-operator surface mine of 2012 among industry peers in the RMCMI's eight-state region.

According to the Mine Safety and Health Administration, whose standards are used to measure mine performances, the national coal industry safety average is 2.35 lost-time incidents per 200,000 employee hours. Coal Creek had zero lost-time incidents in 2012.

"I want to commend the employees of Coal Creek for their unwavering focus on best-in-class safety," Coal Creek's general manager Jim Opfer said.

"Coal Creek is a great example of Arch's philosophy that safety and productivity go hand in hand."

The award marks the second consecutive year in which Coal Creek has been recognized for its safety record.

Coal Creek has exceeded 2.3 million employee-hours without a lost-time incident and has operated the mine for more than three years without a reportable safety incident.

"Coal Creek's total zero incident rate puts you at the head of the pack that is increasingly getting better each year," RMCMI executive director Judy Colgan said.

"Congratulations to all the employees at Coal Creek mine on winning the award, especially for being recognized two years in a row."

The Wyoming mine has 145 employees and sold 10 million tons of bituminous coal in 2011, according to Arch’s website.