"We want to be the benchmark everyone looks to when they mine," Manchin said during the signing ceremony, attended by some of the miners' relatives. "The sacrifice you all have made will change mining in this country."
State lawmakers passed the legislation unanimously just days after a Jan. 19 mine fire killed two men, and about three weeks after an explosion at the Sago Mine across the state resulted in the deaths of 12 miners.
The only survivor among the trapped Sago miners, Randal McCloy Jr., 26, emerged from a light coma Wednesday but still cannot speak.
McCloy was able to chew and swallow soft foods, said Dr. Larry Roberts at Ruby Memorial Hospital on Wednesday. McCloy had been in the coma since his Jan. 4 rescue.
Roberts said McCloy continues to show slight neurological improvement each day.
"The family obviously is thrilled with Randy's constant progress," said Aly Goodwin Gregg, the family's spokeswoman. "They remain optimistic about his continued recovery and they recognize how long the recovery process is going to take."
The state's new mine safety law mandates that miners be provided with emergency communicators and tracking devices. It also requires mine operators to store extra air supplies underground, and sets up a new Mine and Industrial Accident Rapid Response System and statewide all-hours hot line to trigger rescue efforts more quickly.
"It eases our hearts and our pain knowing that maybe this will help save other miners some day," said Delorice Bragg, whose husband died in the mine fire last week.
Federal and state investigators were expected to finally get into the Sago Mine late Thursday to start determining what sparked the explosion that led to the 12 deaths, most of them from carbon monoxide poisoning.
The investigation had been held up, first by the dangerous gases and then over a dispute between the United Mine Workers and the mine's owner involving the union's demand to accompany investigators. The company challenged the union's right to enter the non-union mine after the UMW would not disclose the names of the two miners it is representing. A federal judge ruled Thursday that the UMW could participate.
The Sago disaster and Manchin's calls for reform have spurred several coal mining states to re-examine their mine safety laws.