Irene was born in Superior, Wisconsin to Alice Kirch Smith and Henry Beaver Smith, a railroad union organizer. Youngest of six children, she lived through the Great Depression and was an assistant chemist in WWII. In 1944, Irene married Lloyd “Chris” Christofferson, a submariner in the Pacific. In 1946, they moved to Seattle, raising a family while Chris developed a successful engineering career.

A lifelong learner, Irene earned a BS in Biology at UW in 1966. She volunteered as docent at Burke Museum and Washington Park Arboretum. After retirement, they moved to Useless Bay Country Club near their beloved beach cabin on Whidbey Island. Irene and Chris were married 64 years until his death in 2008. Irene was a regular golfer and active in Dotre av Norge, Whidbey Island Nourishes and Island Athletic Club. Up to her death at age 101, she continued to satisfy her inquisitive mind with family, good friends, and Whidbey Audubon Society. She is survived by children Erika Sweger, Camille Kariya and Steve Christoffferson, and grandchildren Mariko, Erik, Kevin and Lauren. The family plans a gathering for Irene later in the spring.