Mark Jay Groshart, 75, of Dayton, Wyoming, passed away on June 29, 2025 in Dayton. Born on March 2, 1950, in Sheridan to Ralph and Shirley Groshart, Mark grew up sharing a deep bond and many cherished memories with his sister Musette (Groshart) Poll and his brothers Matthew and Mike Groshart.

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Mark lived a full and vibrant life, characterized by dedication, quiet compassion, and a distinctive dry humor that never failed to bring smiles to those around him. After graduating high school he went on and completed two years at Sheridan College. Mark courageously served four years in the United States Navy as a SeaBees mechanic. He bravely served during the Vietnam War and spent several memorable years stationed in Taipei, Taiwan, where he formed lasting friendships and gained invaluable experiences that he carried throughout the remainder of his life.

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Upon his return home from military service, Mark continued ranching with his brother Mike on their family ranches. He was the master of the gravity flow irrigation system on Amsden Creek. For half a century, the Grosharts dedicated their lives together to ranching, preserving their family land, and creating a legacy steeped in enduring values of hard work, integrity, and a deep love for their Wyoming roots.

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On August 14, 1977, Mark married the love of his life, Debbie, in a beautiful ceremony at Amsden Creek Ranch. For 48 years, Mark and Debbie shared an unwavering partnership that inspired all who knew them. Together they welcomed two children who brought them endless joy and pride: son Jay, born in May of 1979, and daughter Amber, born in November of 1980. His joy multiplied with the arrival of his beloved granddaughters, Aliya and Paisley, whom he adored unconditionally, celebrating each milestone with quiet pride.

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After retiring from ranching in 2003, Mark embracingly transitioned into a quieter life at their home overlooking the picturesque Tongue River in Dayton. He filled his time pursuing numerous personal passions, especially his love for reading—Stephen King novels frequently lined his bookshelves. He notably enjoyed adventurous travel trips, particularly fishing excursions in Puerto Penasco alongside his daughter Amber. Time was equally well-spent in Wyoming, engaged in prairie dog shooting adventures with his great friend Howard Page, and sharing enjoyable errands around town with his son Jay.

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Mark was a man of understated warmth, reserved yet unwaveringly empathetic. His sincere care extended not only toward his family and close friends but also to his beloved pets, each frequently treated to generous portions, earning him the family joke of "pet spoiler-in-chief." Over the years, Mark built a special bond with numerous loyal cow dogs, each gaining a unique place within his empathetic soul.

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Mark Jay Groshart will be profoundly missed by his wife Debbie; his children Jay and Amber; his granddaughters Aliya and Paisley; his beloved siblings Musette (Dennis Poll), Matthew(Jan), and Mike(Diana); as well as numerous extended family and countless friends.

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Services honoring Mark’s life will be held Monday, July 7th, at 4:00 pm at the Dayton Community Church, followed by a reception at Dayton Town Hall. In lieu of flowers, donations made to Sheridan and Dayton Search and Rescue and the Dayton Fire Department are deeply appreciated.

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Champion Kane Funeral Home is entrusted with arrangements.

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