Karen L. Mast, 89

Karen L. Mast, beloved mother, wife, grandmother, great-grandmother, great-great-grandmother, and friend, passed away on January 7th, 2026, surrounded by friends. Karen was born on August 7th, 1936, to Maynard and Flossie Berthelson in Shelley, Idaho.

She was raised in Shelley, Idaho, and went to school there. She worked in cafes and spud houses. She married Howard Clark in September 1954, and they settled in Caldwell, Idaho. Howard had a service station, and when he sold out, he bought a diesel and started hauling produce.

The couple moved to Montana in 1975. They adopted two boys, Ken and Steve. Karen started to run with Howard in the truck. In 1996, Howard passed away. Karen sold the truck and started working as a grandma at the Whitehall grade school for the next 17 years. She loved working with the teachers, students, and the other grandmas.

Karen married Dave Mast in 2002. She spent that time helping Dave with trucking until Dave passed away in 2020. After many surgeries on her legs and hip, she got along on a cane. Karen enjoyed her church, The Church of Jesus Christ of Latter-day Saints, and worked in the Relief Society. Michael and Tricia Smith's family helped Karen with everything.

Karen had a great sense of humor, loved animals, loved getting her nails and hair done, and loved getting a hamburger with family and friends. Karen loved gardening, even growing a squash in a pot on the porch one year. Karen was always kind and thoughtful of others and their feelings. She is survived by her brother, Robert Berthelson, her sister, Beverly Grover, and her son, Steve Clark. She is preceded in death by Howard Clark (1996), Dave Mast (2020), and Kenneth Clark (2021).

Per her wishes, there will be a graveside service on January 12th, 2026, at 3 PM at the Whitehall Cemetery in Whitehall, MT, where she will be laid to rest next to Howard Clark.