Obituary is loving written by his family.

Jack Leroy Stees, 81, of Oswego, Illinois, passed away on January 27, 2025, at Rush Copley Hospital in Aurora.

Jack was born July 9, 1943, to Wallace Leroy Stees and Laura Ada Howanstine in Harrisburg, Pennsylvania. He grew up in a small town in central Pennsylvania where his parents taught school. He spent his early years in a two-room schoolhouse in Greenfield. As a child, he and his friends biked through the hills and valleys, fished in the freshwater streams, and enjoyed playing outdoors. He was active in Boy Scouts and achieved Eagle Scout.

After graduating from high school in Chesterfield, Missouri, he studied bacteriology at Indiana University in Bloomington, then earned his Master's degree and PhD in microbiology at the University of Missouri. He was an excellent tennis player, played the clarinet, and enjoyed science clubs.

Jack married his beloved wife of 57 years, Mary Ann Miller, on August 12, 1967. He was honorably discharged as a US Army Medical Corps captain in 1973. From there, he went on to a long career in securities and banking, eventually joining the Northern Trust Company in Chicago in 1977. He retired after 28 years of service.

Jack was known for his friendly smile and kindness. He loved being outside, gardening, or tootling about on his riding mover. He would bike through Kendall County, outmaneuvering the dogs that attempted to intercept him and rescuing injured raccoons. A friendly squirrel he fed continues to leave walnuts for him on the porch. Jack was always interested in meteorology as well. He and his daughter regularly visited Fermilab for Tom Skilling's annual tornado talks. Once she moved to Florida, he sent frequent updates about severe weather and hurricanes. He enjoyed digging into genealogy and learning about history—especially the Civil War—as well as keeping up with scientific developments and listening to the comic stylings of singer Ray Stevens.

Jack was a loving father, grandfather, and brother. He is survived by his wife, Mary Ann; his daughter, Elizabeth; his grandson, Connor; and his sister, Joey Niblock.

In lieu of flowers, the family requests donations to the Church of the Good Shepherd in Oswego, Illinois, or Mutual Ground Women's Shelter in Aurora, Illinois.