KAREN AND DAVID ROCK have operated U.P. Cycle & Sport in Quinnesec for 23 years. (Theresa Proudfit/Daily News photo)

QUINNESEC — The combination of Christmas and snowmobile season makes this a busy time of year for U.P. Cycle & Sport.

With hunting season winding down, the snowmobile trails will be opening soon if the weather cooperates, said Karen Rock, who with her husband, David, has operated the Quinnesec motor sports dealership and service business since 1994.

“As soon as the snow starts to fly,” she said, “people get the itch for snowmobiles.”

Her family is no exception. “Snowmobiling’s always been one of our kids’ favorite things to do,” she said.

U.P. Cycle & Sport grew out of “my husband’s love of motorcycle racing,” specifically motocross, which he competed in for about 15 years, Karen said. They started out servicing machines in a shop on Breitung Cutoff Road, then began offering Suzuki motorcycles and ATVs.

They moved to their current location at W7730 U.S. 2 in 2003 when they added the Can-Am lines of ATVs and Ski-Doo snowmobiles. They also sell dirt bikes, some boats and, increasingly, side-by-sides.

Their versatility and ability to carry several people has made the side-by-sides a popular choice for recreational use, Karen said.

“It’s growing, it’s growing every year,” she said. “It’s become a family sport.”

They still do servicing of machines, with three mechanics on staff.

Their 16-year-old son, Michael, also helps at the store. They have three other children as well: Stephanie, 26, in law school at the University of Wisconsin in Madison; Rebecca, 23, who works at Iron Mountain Animal Hospital; and Josie, 14, still at home.

Michael is involved in the family’s other business, too: bison. Their Rock’s Open Valley Ranch in the town of Fence, Wis., has raised the animals for meat for about eight years, Karen said.

“It was something my husband thought he could do with his son,” she said, adding that Michael “loves animals. I guess we all love animals.”

That can be seen at U.P. Cycle & Sport, where the family’s two golden retrievers, Hank and Duke, are a fixture. “They’re the door greeters,” Karen said. “They greet everyone who comes in.”