Dennie Van Tassel, 79, died in Kirkland, Washington, after a long battle with leukoencephalopathy. Computer scientist, professor, mathematician, author, much loved father, brother, son and companion, Dennie was born in Clear Lake, South Dakota to Rush and Florence Van Tassel.
He had two siblings, Marge and Jim, with whom he remained close his entire life.
Upon graduation from high school, he joined the Marines and was stationed at Camp Pendleton in California. After his service to his country, he completed a BS in Mathematics at the University of Southern California and an MA in Mathematics at California State College, Los Angeles. He put himself through school by working full time for the duration.
After graduating, he settled in Santa Cruz, California where he worked for 25 years as System Administrator at the University of California, Santa Cruz. He subsequently embarked on a second career as Professor of Computer Science at Gavilan Community College, finally retiring 15 years later at age 76.
He was never one for bureaucracy and would frequently skip meetings, to the occasional frustration of the administration. Instead, he put his students first, making himself endlessly available via office hours, labs, and on-line coursework. Dennie also authored five books, wrote magazine articles, and submitted many letters to the editor at newspapers including the New York Times.
His strong work ethic never relented until very late in life, when declining health forced him to slow down.
He married in 1968 and had two children, who were by his side at his passing. His daughter and son have many memories of their father’s boundless energy. Tearing down an old barn and rebuilding it on their urban farm with his son, driving to Baja California in a VW van and camping on the beach, taking long runs through the University hills, donning his bee suit to collect honey from his beehives, and surprising his daughter upon her high school graduation with a trip to Paris and London are just a few examples of his adventurous, generous spirit.
After his marriage ended in divorce he found Marlene Bumgarner, his companion for almost 20 years who was by his side the week of his passing. He helped to parent her youngest child, Deborah Eltgroth, during her high school years, and she considered him her stepfather.

Dennie will be remembered for his generosity, dry sense of humor, unpresuming presence, strong work ethic and love of travel. He is survived by his daughter Sonia Gabrielson (Jacob), son Eric Van Tassel (Rebecca), brother James Van Tassel (Nancy), sister Marge Seuss, and companion and sweetheart Marlene Bumgarner, along with four beautiful grandchildren (Jessica, Nathan, Blake and Chloe) and many other friends, colleagues and family members.
All will miss him dearly.
A Celebration of Life will occur on October 7, 2018 at 2:30pm at Peace United Church of Christ, 900 High Street in Santa Cruz, California.
In lieu of flowers or gifts, please consider a donation to the Monterey Bay Aquarium.
