Rescuers prepare to carry Serenity Coyne of Boston after she was injured by a falling rock while climbing Dorr Mountain Ladder Trail in Acadia National Park on Labor Day. Credit: Courtesy of Michael Coyne

Surgeons were working Wednesday to repair the shattered left leg of a professional adventure sportswoman hit by a falling rock in Acadia National Park.

Serenity Coyne of Boston was undergoing her second operation at Eastern Maine Medical Center of Bangor since the Labor Day accident on Dorr Mountain Ladder Trail. The 53-year-old was descending and between trail ladders when the 400- to 500-pound rock smashed her leg, according to her husband, Michael Coyne.

Coyne was in fair condition as of late Wednesday afternoon, according to a hospital spokesman. He said he could provide no further details.

Since 1995, the Coynes have climbed Mount Kilimanjaro, the Bolivian Andes, the Canadian Rocky Mountains, Devil’s Tower in Wyoming and Mount Gros Morne of Newfoundland to raise money for various causes for their charity, Expedition Outreach, Michael Coyne said.

Michael Coyne said he and his wife have faced many life-threatening situations over the years. He earned a Guinness Book World Record in Bolivia for the highest altitude Luge descent, is a U.S. Marine Corps combat veteran and was almost beaten to death by an assailant while he was a Massachusetts state trooper.

Serenity Coyne is facing a daunting future — she might lose her leg — with a characteristic determination, Michael Coyne said.

“Now our whole life is going to be about her,” Michael Coyne said Wednesday. “She told me that in one year, she is going to run a triathlon. I am actually terrified of the swim portion of it, but she looked at me and said, ‘You’re going to do it, too.’ I said ‘all right.’”

“She is way braver than any Marine I ever met on the battlefield. She is the most courageous person I know,” Michael Coyne added. “She is already talking about making something good come out of this. It just blows my mind.”

The first operation, microscopic surgery on Monday, rid the wound of dirt that got into the leg when Michael Coyne wrapped his shirt around it to stem bleeding, he said.

When the accident occurred, the Coynes were on a steep cliff between ladder sections of the trail a third of a mile from the trailhead. The emergency was reported at 7:19 a.m. and about 30 minutes later, park rangers and paramedics from the Bar Harbor Fire Department arrived, park officials have said.

“The life-threatening thing was the blood loss and shock,” said Michael Coyne, who was also hit by the rock and suffered a bruised back.

They moved Serenity Coyne to a ledge, lowering her roughly 30 feet with a rope and a litter before a Maine Forest Service helicopter flew her to a Bar Harbor ball field. An ambulance brought her to Mount Desert Island Hospital of Bar Harbor before she was flown to Bangor, Michael Coyne said.

Michael Coyne said he is grateful to all the rescuers, particularly the Bar Harbor paramedics. He hopes to get some of his sponsors to buy them more equipment, such as water bottles, and encouraged residents to contribute to the Bar Harbor Fire Department.

“They were faster than everybody,” he said. “They put me to work and I started an IV, and they got some pain meds in her right away — less than an hour after the accident. They were there so fast. And they had to hike all the way up there.”

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