LtCol Siebenthal was born in Knox, Indiana and is a graduate of Long Beach State University. He was commissioned in 1983 as an infantry officer. Prior to his commissioning he completed a 4 year tour in the enlisted ranks, attaining the rank of Sergeant. As a Marine Corporal, he won the Navy Northern European Middleweight Boxing Championship while stationed in Holy Loch, Scotland aboard the submarine tender, “USS Holland”.
His company grade assignments included Platoon Commander and Executive Officer, Company “A”, 1stBn, 7th Marines; Commanding Officer, Company “B, 1st Recruit Training Battalion MCRD, San Diego; Assistant Director of Drill Instructor School (San Diego); Student, Infantry Officer Advance Course in Fort Benning, Georgia; Commanding Officer, Company “A”, 2d Reconnaissance Battalion; Commanding Officer, Company “K”, 3rd Bn, 2d Marines and Inspector-Instructor, Company “B”, 25th Marines in Manchester, New Hampshire.
As a reserve field grade officer, LtCol Siebenthal served as the Commanding Officer, Company “B”, 6th Engineer Support Battalion in South Bend, Indiana. He was the Deputy Commandant of Culver Military Academy (Indiana) when he was re-called to active service in January of 2002 in support of Operation Enduring Freedom. He served 3 years as a staff officer in the G-3, II Marine Expeditionary Force and was then assigned as the Senior Watch Officer for II MEF Forward, Camp Fallujah, Iraq.
LtCol Siebenthal graduated with honors from The Basic School (first in Leadership).
LtCol Siebenthal’s personal decorations include the Bronze Star, Meritorious Service Medal, Navy-Marine Corps Commendation Medal with three stars and Navy Achievement Medal.