It was 35 degrees and frost glittered on the undergrowth as Rosemarie “Ro” Mason popped the hatch of her Jeep Cherokee parked at a trailhead off a rural road in New Jersey’s Pine Barrens.

She began handing out equipment to a group of 14 volunteers before issuing instructions. Her sister, Diane Mason, stood nearby inspecting a gas-powered weed whacker for the day’s work ahead.

“Everybody be safe!” Ro shouted. “It’s cold, so stay warm. And don’t touch any plant you don’t know, or don’t touch any animal you don’t know.

“And,” she added with a smile, “don’t touch any people you don’t know — unless they say it’s OK, of course.”

The sisters are trailblazers, literally and figuratively.

Their unpaid task: Keep clear the 53.5-mile Batona Trail that cuts through the heart of the New Jersey’s 1.1 million-acre Pinelands National Reserve. They cut briar, fill ruts left by ATVs, repair footbridges, reinforce berms eroded by beaver dams, snip branches. And they mark trees with the pink paint that denotes the trail.

Each Tuesday they meet with a dozen or more volunteers, many regulars, of the Outdoor Club of South Jersey to clear a mile or two of path. They gather at the end for a tailgate picnic organized by member Pat Burton. Last year, the tight-knit group logged 800 hours of volunteer time.

Ro, 66, a retired assistant slot manager for an Atlantic City casino, has led the trail maintenance for 20 years. Diane, 58, who worked for the Atlantic County court system, promptly joined her sister on the trail after retiring three years ago. Previously known as the Povse sisters, Ro and Diane coincidentally married men named Mason, though they’re not related.

The trail they maintain has its origins in Philadelphia. In 1961, a group of city residents in the Back to Nature Hiking Club, shortened to Batona, began building a trail in the Pine Barrens with permission from the state.

The trail, expanded to 53.5 miles, runs through the Franklin Parker Preserve and Bass River and Wharton State Forests, winding like the native timber rattlesnake through or near some of the Pinelands National Reserve’s most iconic spots, including from north to south: Ongs Hat, Apple Pie Hill, Lower Forge, Quaker Bridge, Batsto, Martha, and Lake Absegami.

The Outdoor Club of South Jersey, under Ro’s leadership, has taken on the bulk of the work to keep the trail open. The state does not have the budget for it. Diane handcrafts signs, mimicking those made by the state.

The sisters joke that although they have never hiked the trail straight through, they’ve covered it many times, one mile at a time. They work in snow, ice, and rain, but not in summer, when the Pine Barrens’ notorious heat, chiggers, and ticks all peak.

“We usually start at 10 in the morning and work until noon,” Ro said. “That’s all we can handle. It’s hard work. We work in three state parks, and on three other trails that need love.”

Ro also organizes hikes for the outdoor club, which she got involved with 30 years ago.

“The Outdoor Club has been very good for me,” she said.

About two decades ago, a trail leader asked if Ro could help maintain a section of the Batona Trail off Evans Bridge and Route 563. At that time, the leader had suffered a stroke, so no one was maintaining the trail.

The original Batona hiking club was responsible for keeping clear the northern 20 miles of trail, but its membership was small and aging.

“There was so much to be done, that I realized with three or four people we still couldn’t do it all,” Ro said.

She reached out to other club members. Only a few showed at first, but the group grew steadily and Ro continued as leader.

Each week, she hands out cutters, loppers, paint, rakes, and whatever else is needed. Some members bring their own. Most of the work is manual, though they do use gas-powered equipment if needed. They don’t use chainsaws, for liability reasons. If something big needs cutting, they reach out to a state park manager.

“We’re trying to leave a majority of the trees that come down because it keeps out the dirt bikers,” Ro said. “We have a big problem with dirt bikers. They tear up the trail bed, and the ruts fill with water. So we leave anything hikers can climb over. After all, the trail has to have some wilderness feel to it.”

Ro said maintaining the trail is “a labor of love.”

Frank Pearce, 75 and a retired pharmacist, was volunteering with the group on Tuesday, a brilliantly sunny day sandwiched between heavy rains and a snowstorm.

“Ro is unbelievable,” Pearce said. “And she makes it an event with a tailgate at the end. Sometimes there are games.”

Diane was nearby clearing low-lying briar, trying to keep a path one foot wide on either side of the trail.

“This area would all be overgrown in two years if we weren’t out here,” she said, pointing to a path the group had been working on. “We try to get to each spot of the trail every other year.”

She said the Outdoor Club of South Jersey could use younger members to join the club and help.

“It’s good exercise,” she said. “And it’s a good excuse to get into the woods.”

If you’re interested in joining the Outdoor Club of South Jersey (disclosure: I’m a member) visit https://www.ocsj.org/join-us.