General Mongeon served the Army and the Quartermaster Corps with distinction for 35 years. He was commissioned in the Regular Army through the ROTC program at the University of Arizona. During his formative years, he served in a variety of Quartermaster positions to include: Division Property Book Officer of the 4th Infantry Division (Mechanized); Commander, HHC, DISCOM, 4th Infantry Division; Military Assistant to the Deputy Chief of Staff for Logistics, HQDA; S-3 and Executive Officer of the 2nd Forward Support Battalion, 3rd Infantry Division; Deputy G-4, 3rd Infantry Division; and Aide-de-Camp to the Supreme Allied Commander Europe.
General Mongeon served in the following key positions: Commander, 3rd Support Squadron of the 3rd Armored Cavalry Regiment, 18th Airborne Corps in OPERATION DESERT SHIELD/STORM; Commander, 41st Area Support Group in Panama; Deputy Director for Logistics, Readiness and Requirements, J-4, The Joint Staff; Commander, Defense Supply Center, Philadelphia; Director of Sustainment, Office of the Deputy Chief of Staff, Logistics, HQDA; Deputy Chief of Staff, G-4, United States Army Forces Command; and Director, Logistics Operations, J-3, Defense Logistics Agency.
General Mongeon’s awards and decorations include the Distinguished Service Medal with oak leaf cluster, Defense Superior Service Medal with oak leaf cluster, Legion of Merit with two oak leaf clusters, Bronze Star Medal, Meritorious Service Medal with two oak leaf clusters. General Mongeon was inducted as a Distinguished Member of the Quartermaster Corps in 1988.