SgtMaj Vandentop graduated from Upland High School in Upland, California. He enlisted in the Marine Corps and reported to MCRD, San Diego on 23 October 1995 for recruit training. Upon his graduation as a Private First Class in January 1996 he reported to Marine Combat Training at Camp Pendleton and then attended his MOS school of Basic Supply Course at Camp Johnson, North Carolina from March 1996 to October 1996.
In November 1996, Private First Cass Vandentop reported for duty to 4th Tank Battalion, San Diego California where he held a billet of Fiscal Clerk. During this tour PFC Vandentop completed a deployment to Norway in Support of exercise Battle Griffin and was promoted to Lance Corporal on 1 December 1996 and meritoriously promoted to Corporal on 2 October 1997.
In May 1999, Corporal Vandentop reported for I-I duty to 4th Low Altitude Air Defense Battalion, Pasadena Ca where he held the billet of Supply Clerk and Supply Chief. While serving with 4th Low Altitude Air Defense, Sergeant Vandentop attended Survival Evasion Resistance Escape (SERE) School in October 1999 and the Ground Supply Chiefs Course in February 2002.
In September 2003, Sergeant Vandentop reported to Drill Instructor School, MCRD San Diego. Upon Graduation in December, He was assigned to I Company, 3rd Recruit Training Battalion and Instructional Training Company, Support Battalion where he held the billets of Drill Instructor, Close Combat Instructor and Martial Arts Training Facility SNCOIC. Sergeant Vandentop attended Martial Arts Instructor Course in June 2004, Martial Arts Instructor Trainer Course, Close Combat Instructor Course and Combat Conditioning Specialist Course in February 2006 and the Static Rope Suspension Trainer (SRST) Master Course in June 2006. He was promoted to the rank of Staff Sergeant on April 1st 2006.
In February 2007 SSgt Vandentop reported to I MEF Headquarters Group and filled the billets of Company Gunnery Sergeant, Civil Affairs Team SNCOIC, and Corporals Course Chief Instructor. From January 2008 to February 2009 he deployed with the Civil Affairs Group as the SNCOIC and Pay Agent to Fallujah Iraq in support of Operation Iraqi Freedom. On October 2nd 2008 he was combat meritoriously promoted to the rank of GySgt. From January 2010 to January 2011 he deployed as Company Gunnery Sergeant to Helmand Province, Afghanistan in support of Operation Enduring Freedom. He attended the Advanced Course in February 2011 where he graduated as the Gung-Ho Recipient.
In May 2011 Gunnery Sergeant Vandentop reported to Headquarters and Service Battalion, MCRD San Diego for duty as Supply Chief and Company Gunnery Sergeant. He was promoted to the Rank of First Sergeant on April 1 2012 and attended the First Sergeants course in April 2012.
In May 2012 1stSgt Vandentop reported for duty to Marine Corps Communications Electronic School, Twenty-nine Palms California for duty as Headquarters and Service Company First Sergeant and Air Control Training Squadron Sergeant Major. First Sergeant Vandentop attended the Navy Senior Enlisted Legal Course in June 2012 and the resident Marine Corps Senior Enlisted Professional Military Education in Quantico Virginia in April 2014.
In February 2015 First Sergeant Vandentop reported for duty to 3rd Assault Amphibian Battalion, 1st Marine Division where he held the billet Company First Sergeant for E, C and H&S Company. In November 2015 1stSgt Vandentop completed a unit deployment program with AAV Company to Okinawa Japan and was attached to Combat Assault Battalion, 3rd Marine Division. During this period he supported exercises in Korea, Cobra Gold 15, Balikitan 15 in support of the 31st Marine Expeditionary Unit and 3rd Marine Division. He was promoted to the rank of SgtMaj on March 17 2017.
In May 2017 SgtMaj Vandentop assumed the duties as Battalion Sergeant Major, 3rd Transportation Support Battalion, Combat Logistics Regiment 3, 3rd Marine Logistics Group, and Okinawa, Japan. During this tour he supported a wide spectrum of exercises across the Indo Pacific Area of Operations to include Freedom Banner Ssang Yong, Korean Military Exchange Program, Balikitan, Cobra Gold as well as support to the 31st Marine Expeditionary Unit.
His personal awards include the Meritorious Service Medal (w/ 2 gold stars), Navy/Marine Corps Commendation Medal (w/ 2 gold stars), Navy/Marine Corps Achievement Medal (w/ 4 gold stars), Military Outstanding Volunteer Service Medal, Drill Instructor Ribbon and the Combat Action Ribbon.