Diana Zimmerman was born in North Dakota in 1949 to Lawrence and Josephine Zimmerman. Her fondest childhood memories were of spending time with her brother Roger and other relatives on the family farms between Anamoose and Minot. After high school, she lived in California and Washington, but eventually settled in Montana in the early 1970s, raising her three sons, Aron, Galen, and Kevin, in and around Boulder and Helena. Diana worked as a librarian for many years, eventually retiring from the Lewis & Clark Library in 2014. Always drawn by the southwest, she spent a few years in Arizona after retiring, but Montana beckoned her, and she returned to Helena in 2017. 

Diana loved being a mother, and later, a grandmother. She was also a close friend to many, known for her intellect, wit, generosity, and compassion. The enduring friendships she developed at work, in her Dream Group, through her children's friends and families, and indeed everywhere she went, brought her deep happiness and sustained her through challenging times. 

Diana was a wanderer. She travelled across the U.S. and abroad, both to visit her children and relatives and to explore. She especially enjoyed road trips and camping in the West, be it alone or with family and friends. An inspiring cook, she relished sharing homemade meals and stories with visitors around the kitchen table. Diana was also an avid gardener, a voracious reader, and an accomplished artist and calligrapher. Her artwork adorns the walls of her many friends and family. 

Diana was famously tenacious and resilient, having bounced back from many setbacks and illnesses throughout her life. Ultimately, she succumbed to complications related to cancer and pneumonia, but not without a fight. She held on against the odds, laughing and reminiscing with a steady stream of friends and family before passing peacefully on January 28th, 2026 at St. Peter's Hospital in Helena. 

Diana was preceded in death by her parents, brother, husbands, and her beloved youngest son, Kevin. Diana is survived by her two eldest sons and their families. Aron Smetana lives in Northern California with his wife Carrie and their teenage daughters Sadie and Emma. Galen Halverson lives in Montreal with his wife Alayne and their teenagers, Leo and Audrey. Friends and family will be invited to a memorial service in June near Helena.