Dennis Lee Osterberg

Dennis Lee Osterberg, adoring husband and partner of Rebecca Osterberg, passed away on April 6, 2026 in Madison, Wisconsin, Dane County. He was 77. 

His death, at William S. Middleton Memorial Veterans Hospital, following a brief ICU hospitalization, was attributed to a severe and long-time pulmonary illness his doctors correlated to military exposure to Agent Orange. In the presence of his family, Dennis was offered a final salute at the hospital’s nurses station as Taps played during the emotional farewell. 

Dennis is survived by Rebecca; his children and grandchildren: Matthew and Rebecca Keller (Luke), Tina Little (Sehana Leean), Joshua and Stacey Osterberg (Sariya, Maddox, Sofie and Collins), Jacob and Kelly Osterberg (Reese and Theo), his dear friend and the mother of his children, Gail Osterberg; his brother Robert Osterberg, his sisters-in-law Sharon Osterberg and Cindy Osterberg and countless family, from his cousins to his nieces and nephews, to his brothers and sisters-in-law, who he considered his own.

He was born on November 22, 1948 to Russell and Maxine (Freitag) Osterberg. He was preceded in death by his parents and his siblings Gary (died in infancy), Mary (Terry) White, Dale (Sharon) Osterberg, Brian (Cindy) Osterberg, and his sister-in-law Valerie (Robert) Osterberg. He crosses the infamous Rainbow Bridge to join Tippy, StarBuck, SmokeyBear and Archer, his adored canines. 

Dennis served as a light weapons infantryman in the 1st Cavalry Division, 2nd of the 7th U.S. Cavalry, as part of the first U.S. Army troops deployed to Vietnam. In a valiant act of love and brotherhood, Dennis demonstrated selflessness and care to a fellow soldier. When his outpost was attacked, and his dear friend Vernon Rainey was shot, Dennis carried him to a helicopter with consciously caring and disciplined demeanor. While his friend passed away, the act of not leaving anyone behind lived on in the memories of those who recall the situation.

His military awards and recognitions include: The National Defense Service Medal, Vietnam Service Medal with one Bronze Service Star, Republic of Vietnam Campaign Medal, Army Commendation Medal with one Oak Leaf Cluster Air Medal, Combat Infantryman Badge, Sharpshooter (Rifle), Sharpshooter (M60 MG), Sharpshooter (Pistol), Expert (M-79 GL). Dennis was deeply appreciative of his fellow veterans for “being there with and for me,” including Lonnie L. Leech, Dean Reisch, Ron Montgomery, James Ferrone, and Vern Rainey. 

Dennis, affectionately known as Denny, was a 1966 graduate of Belvidere High School, and studied at Northern Illinois University. He worked in the aerospace and defense sector following his military service, dedicating decades of his professional career to Textron and Woodward Governor. Dennis was “a trusted advisor, decision maker, and a key player in the day-to-day operations as well as providing unique strategic input for complete reorganization of the operations… that made us one of the most productive organizations that eventually ended up in Woodward,” according to his former supervisor and friend, Bill Neely.

An advocate for mental healthcare in his retirement, Dennis was active in a Vietnam Veteran mental health support group in northern Illinois. In previous years, he coached baseball, volunteered as a swim officiant for the YMCA, and loved all of Chicago’s sports teams.

Dennis, an avid fisherman since his youth, felt most alive with a fishing pole in hand at his family’s vacation home at Big Rock Resort on Leech Lake. He and Rebecca bought a spot where he spent his youth. He loved woodpeckers, hummingbirds and any other birds that made themselves visible at his feeder stations there or at home. Squirrels and Dennis, however, they didn’t see eye to eye. He was known to feel like a kid while on the water – especially when in the company of Rebecca, his children and his grandchildren. Some of his favorite catches included jumbo perch, northern pike, walleye, smallmouth and rock bass. 

Dennis was a tissue donor and his gift will offer life to others. Those who are interested in becoming tissue and organ donors are encouraged to register in his honor.  

Join in honoring the life of Dennis at the 11 a.m. to 2 p.m. visitation on Sunday, April 19, 2026, at the Belvidere Funeral Home, 203 Logan Ave., in Belvidere, Ill with a service and military honor guard ceremony at 2 p.m. A late lunch will follow at the Belvidere VFW Hall, 1310 W. Lincoln Ave., of which he was a lifetime member. Graveside services will be held at 10 a.m. Monday, April 20, 2026 at East Bonus Cemetery, 10732 County Road 11, in Garden Prairie, Ill. 

In lieu of flowers, tribute donations are requested to be made to the Wounded Warrior Project at woundedwarriorproject.org

His family thanks the VA doctors, nurses, and staff for the support, dignity, and care they provided to him in his final days.