Portia Matthiesen Bismarck ND Obituary, Death; Highway 83 Head-On Crash

The Mandan community mourns the passing of Portia Elbie Matthiesen, age 21, who died February 8, 2026, following injuries in an automobile accident. In light of the community’s generous floral tributes, the family requests that anyone wishing to honor Portia instead consider donations to Furry Friends Rockin Rescue, in memory of her love for animals.

Portia was born on September 4, 2004, to Troy Matthiesen and Jessica (Schlosser) Wright and was a beloved sister to Brodey and Parker. She was her mother’s best friend and confidant and cherished by her father from her earliest days. Portia attended St. Joseph’s Grade School, Mandan Middle School, and graduated from Mandan High School in 2023, excelling academically and in athletics, particularly soccer.

She met her fiancé, Seth Boyko, while working at Jack’s Steakhouse, and the two quickly became inseparable. Portia loved adventure, the outdoors, flying crop planes with Seth, and building a life together on their farm. She earned a business degree from Bismarck State College and worked at Bed ’N’ Biscuit Ranch, training and caring for dogs, while pursuing her goal of becoming a large-animal veterinarian. She recently returned from Texas, certified in cattle pregnancy checking, artificial insemination, and ultrasound, and was preparing to launch her own mobile veterinary service.

Portia’s vibrant personality, infectious smile, quick wit, and zest for life brought joy to family, friends, and coworkers alike. She loved deeply, lived fully, and will be forever missed.

Visitation will be held Friday, February 13, from 5:00 to 7:00 p.m. at Parkway Funeral Service, followed by a prayer service at 7:00 p.m. Funeral services are scheduled for 11:00 a.m. Saturday, February 14, 2026, at Evangel, Main Auditorium, 3225 N. 14th St., Bismarck, with burial at Fairview Cemetery at 3:00 p.m.

Portia is survived by her parents, siblings, fiancé, grandparents, aunts, uncles, cousins, and extended family, and was preceded in death by her paternal grandfather Robert Matthiesen and her great-grandparents.