Randy Marvin Grieser

Randy M. Grieser, 75, left this world unexpectedly from a massive heart attack on Saturday, May 9, 2026, leaving his family, friends and kittens heartbroken.

Randy was born on September 3, 1950, the second oldest among four brothers to the late Marvin and Alvina (Cole) Grieser. Randy married Kathryn M. Sitko on July 10, 1976, and together they had one wonderful son, Matthew, that Randy was very proud of.

Randy graduated from Mosinee High School in 1968 and chose to immediately enlist in the US Airforce attending basic training at Lackland Airforce Base in San Antonio, Texas. After basic training, he trained becoming a jet aircraft mechanic while attending Jet School at Sheppard Airforce Base in Witchita Falls, Texas in 1969. Later, Randy was assigned to Duluth Airforce Base working as a Transit Alert Airman where he secured and maintained military aircraft. In 1970, a US Airforce Colonel, who was a pilot, presented Randy an amazing opportunity to be assigned to Germany to work on fighter Jets which he gladly accepted. While stationed in Bitburg, Germany, he worked as a jet mechanic on various military aircraft, including F4 Fighter Jets. Randy ultimately earned the designation as Crew Chief, where he took on the responsibility of overseeing aircraft operations of assigned fighter jets until 1972 when he was discharged from the US Airforce. His technical aircraft expertise led him to later career opportunities where he worked as an Aircraft Mechanic for several commercial airlines working on Fokker F27’s and Metro aircraft for Midstate Airlines and Chicago Air based in Mosinee. His other employment included assembly at Drott and Final Unit Inspector at JI Case, Plant Foreman at Schofield Enterprises, and Shift Lead Supervisor at Greenheck Fan Corporation until his retirement in 2016. Additionally, throughout his employment history, Randy took on a business partnership creating “Enlona-Facil” by Tuisse & Grieser Johnson, Ltda, a specialized, automated truck tarping system in Brazil.

Those who knew Randy knew what a fun free-spirited person he was! He loved people and people couldn’t help loving him! He was known to make his “weekly rounds” at the local establishments on a routine schedule meeting his buddies to enjoy his favorite beverage (Pabst!), catch up on recent news, or play Sheepshead on Tuesday nights. He made many, many friends during these visits and everyone looked forward to seeing him. He loved his 1956 Chevy Belair and taking it out on weekend rides and enjoyed his pontoon on Halfmoon Lake. Randy enjoyed traveling outside the State and would even take an occasional trip to the casino with Kathy!!!

Randy is survived by his wife of 49 years, Kathy, son, Matthew Grieser, and grandchildren, Justin and Kirstin. He is further survived by his brothers, Danny Grieser (Birnamwood) and Alan Grieser (Craig, Colorado), sisters-in-law, Mary Jo Maly (Mosinee) Margaret (Mugsie) Grieser (Mosinee) and Yvonne Sitko (Wausau) as well as many nieces and nephews.

Besides his parents, Randy was preceded in death by his brother Brian Grieser (Florida), brothers-in-law, Kenneth Sitko and Jeffrey (Lenny) Maly, sisters-in-law, Diane (Danny) Grieser and Martha (Alan) Grieser and father and mother-in-law, Edward and Marcella Sitko. Last, Randy is survived by “his boys”…..Dobie and Gillis”.

A Mass of Christian Burial will take place at 12 pm, on Monday, May 18, 2026, at St. Paul Catholic Church, Mosinee. The Rev. Aaron Becker will officiate. Burial will take place at St. John the Baptist Catholic Cemetery, Peplin. Visitation will be from 9:00 a.m., until the time of service, all taking place at the Church. Beste Funeral Home, Mosinee, is assisting the family with arrangements. Online condolences can be directed to the family at www.bestefh.com.

Randy was one of the most patriotic persons we’ve ever known. He was an active member of the Peplin VFW from its establishment and served twice as its Post Commander. He was so proud to serve our country and felt privileged to go on the Never Forgotten Honor Flight to Washington D.C. in October, 2023. Fly High, Randy! Be with the “Spirit in the Sky”!