Dennis "Denny" Eugene Wynn's lifelong love of the wilderness began in 1954 at Camp Tepe-Tonka on Big Stone Lake, Minnesota. He started there as a camper and returned as a counselor, teaching archery and canoeing – the first of many adventures that would define his life.

Denny was born on October 4, 1944, in Creston, Iowa, to Robert and Phyllis Longmore Wynn. The oldest of three children, he grew up in South Dakota, where he developed a passion for hunting and fishing while living in Mitchell, Yankton, Watertown, and Sioux Falls. He graduated from Washington High School in Sioux Falls in 1963.

A dedicated student and lifelong learner, Denny attended several institutions including the University of South Dakota (Vermillion), Sioux Falls University, Augustana University, Missouri State University in Kirksville (now Truman State), the South Dakota School of Mines, the University of Idaho (Moscow and Pocatello), the University of Utah, and the University of Iowa. He also studied in the field on the Juneau Icefield in Alaska. He earned his B.S. in Psychology and Biology in 1968 and later received a Master's in Geology and Environmental Science from the University of South Dakota in 1981.

In 1968, Denny married Donna Hilligoss and together they built a life in Sioux City, Iowa. They welcomed two children, Dawn and Donovan Jay (DJ). Though the marriage ended in 1988, the family remained a central source of joy in his life.

Denny began his professional journey as a Juvenile Parole Officer for the State of Iowa (1968–1970) and then served as Director of St. Anthony's Boys Group Home through Catholic Charities (1970–1973). From 1973 to 2000, he dedicated himself to teaching in the Sioux City Community School District, impacting generations of students at Floyd School, North Junior, North High, and West High.

His summers were often spent outdoors: working in the White River National Forest in Colorado through a student volunteer program, serving as a wilderness ranger in Buffalo, Wyoming, and leading student expeditions through the Boundary Waters in Minnesota and Canada. He also co-owned "The Blue Knight," a converted school bus used by the Soo-Land Ski Club.

After retiring in 2000, Denny moved to Dillingham, Alaska, to teach special education. There, his passion for nature and science led him to work with the U.S. Fish & Wildlife Service, conducting wildlife surveys in the Togiak National Wildlife Refuge. He later worked as a biological technician in the Maritime National Wildlife Refuge out of Homer, Alaska, and even spent time commercial fishing in Bristol Bay.

In 2010, Denny married Debra Dykstra. Together, they shared countless adventures – from the Aleutian and Pribilof Islands of Alaska to the mountain parks of Idaho and Colorado. Their shared passion extended to W-D Home Improvement, a small business that helped families who couldn't secure traditional bank loans become homeowners. They found joy and purpose in rebuilding homes and rebuilding lives.

In 2014, Denny's deep respect for nature culminated in the permanent conservation of his cherished 150-acre native prairie in the Loess Hills of Iowa, through an easement with the Iowa Natural Heritage Foundation – ensuring the land he loved would be protected forever.

Denny found his greatest joy in his family. He was immensely proud of his children, Dawn Wynn (with partner Markjon Trierweiler), DJ Wynn (with wife Kirsten), and his bonus son, Cole. He adored his grandchildren – Jackson (with Wife Alexa), Sydnee, and Samantha Wynn – who knew him affectionately as "Poppy."

He is survived by his beloved siblings, Charles "Chuck" Wynn and Cherie Wynn Hayworth.

At Denny's request, there will be no wake or funeral. Instead, his ashes will be spread on his treasured prairie. All family and friends are invited to celebrate his extraordinary life at his log home – a gathering filled with stories, laughter, and love, just as he would have wanted will be held on October 4, 2025.