Catherine Heppner loved the outdoors, whether gliding down the slopes at Sunday River Resort with her husband and son, skimming across Northwood Lake on a wakeboard, or sitting around the campfire. Her life was filled with adventures, laughter, and love, those who knew her said.

On Sunday, Heppner, 46, was fatally stabbed at the headquarters of the Timberland shoe company in Stratham, N.H., where she worked as a marketing director. Robert Pavao, who worked at Timberland as a security guard, was arrested and charged with second-degree murder. The motive is unclear.

Heppner, known as Cassie, had a warm, fun-loving personality and will be deeply missed, her colleagues said.

“Cassie was truly one-of-a-kind, and her passing leaves a void that will never be filled,’’ the company said in a statement. “We extend our deepest condolences to her family and loved ones.’’

Heppner served on the national council for Big City Mountaineers, a nonprofit organization that gives teens the chance to experience the outdoors.

Bryan Martin, the group’s executive director, said he met Heppner five years ago but it felt like “we’d known one another forever.’’

“She was a wonderful colleague and dear friend,’’ he said in a telephone interview. “It’s just really heartbreaking to lose her.’’

Pavao, 20, had no relationship to Heppner, officials said. In his Department of Corrections interview report, officials wrote “doesn’t know’’ in describing his connection to her.

Pavao was employed by Securitas and had worked for four months at Timberland and a second company, Lindt, according to court records. He lives in Berwick, Maine, with his parents. He had no history of mental health or substance abuse issues, records show.

Pavao has pleaded not guilty and is being held without bail.

In a statement, Heppner’s family said: “We are devastated and stunned by the tragic loss of our beloved Cassie.’’

“She was the energetic light of our family, with an infectious spirit that touched anyone in her presence,’’ the family wrote. “She was a wonderful wife, mother, daughter, sister, friend and colleague. We will cherish her forever.’’

According to her obituary, Heppner was born in Katonah, N.Y., and was president of her class at John Jay High School, where she served as captain of the lacrosse and field hockey teams. She graduated from the University of New Hampshire in 1995.

“She may not have been the tallest person in the room, but she had the biggest heart and personality,’’ her obituary read. “Depending on the season, you could find Cassie shredding ‘Dream Maker’ at Sunday River Resort in Maine with her husband, Mike, and son, Jack; wakeboarding on Northwood Lake in New Hampshire; or cheering for the Yankees while wearing a Red Sox jersey.

“Cassie had so much to be proud of in her life, from her career where co-workers weren’t just colleagues but best friends, to her countless adventures and volunteering across the world, to her loving home and closely knit neighborhood.’’

A celebration of Heppner’s life is planned for Feb. 16 from 1 to 4 p.m. at Stockbridge Funeral Home in Exeter, N.H.

Heppner’s family have begun a fund-raising campaign to create a scholarship fund “to help young women reach new heights by challenging themselves in the outdoors, as Cassie did,’’ according to a GoFundMe page.

’’As Cassie herself would enthusiastically say, while giving you a giant bear hug, “LET’S DO THIS!’’ it read.

Emily Sweeney can be reached at emily.sweeney@globe.com. Follow her on Twitter @emilysweeney. John R. Ellement can be reached at john.ellement@globe.com. Follow him on Twitter @JREbosglobe.