According to a report in local newspaper the Farmington Daily Times, the machines restarted on May 4.
Its mine-mouth facility, the San Juan generating station in Waterflow, remained open throughout, thanks to a large reserve stockpile.
Employees were either given alternate task orders or transferred to BHP’s sister mine Navajo during the idle.
No individuals were furloughed.
“We appreciate the hard work and support of our employees, our suppliers and MSHA [Mine Safety and Health Administration], as well as the various government entities in working with San Juan mine to safely resume operations,” New Mexico Coal president Jac Fourie said.
“Our core focus continues to be the safety and wellbeing of everyone working in the mine.”
NMC is a US subsidiary of Australia-based BHP.
San Juan, which employs about 580 people, suffered no injuries in the fire that began on September 10.
Crews injected nitrogen gas to extinguish it and the longwall panel was subsequently sealed in two phases with foam cement and permanent concrete seals later, the paper said.
The mine produces about 6.9 million short tons annually.
Its San Juan generating station provides about 1800 megawatts of electricity from four units.
An MSHA spokesperson was not available to comment on San Juan’s restart.