CSM Jenks entered active military service in the United States Army at Fort Benning, GA in June of 1981. After Basic Infantry Training (OSUT) and Airborne School, he served in numerous Light Infantry and Airborne assignments in the United States and Overseas. In 1986, CSM Jenks completed his enlistment on active duty and entered the National Guard.

Since 1986 Sergeant Major Jenks served in several Combat Arms positions from Squad Leader, Platoon Sergeant, and First Sergeant. In 1999, he was selected and promoted to CSM. As a Command Sergeant Major he has served as an Infantry Battalion CSM, as Regional Training Institute (RTI) Commandant CSM, as an Infantry BDE CSM and an Infantry Brigade Combat Team CSM. In 2003, CSM Jenks served in Operation Enduring Freedom, Afghanistan with 2d Brigade 10th Mountain. In December of 2006, CSM Jenks served as 29th Infantry Division (Forward) CSM MNTF-E. CSM Jenks currently serves as the Division Command Sergeant Major of the 42d Infantry Division.

CSM Jenks has completed PLDC, BNCOC, ANCOC, and the United States Army Sergeants Major Academy.

CSM Jenks has received the following awards: Legion of Merit, Bronze Star Medal, Meritorious Service Medal (with 2 bronze oak leaf clusters), Army Commendation Medal (with 4 bronze oak leaf clusters), Army Achievement Medal (with 2 bronze oak leaf clusters), Good Conduct Medal, Army Reserve Components Achievement Medal (with 2 bronze oak leaf clusters), National Defense Service Medal (2nd Award), Kosovo Campaign Medal, Afghanistan Campaign Medal, Global War on Terror Expeditionary Medal, Global War on Terror Service Medal, Humanitarian Service Medal (with 1 bronze oak leaf cluster), Armed Forces Reserve Medal ( “M” device 4th award, bronze hourglass), NCOES Ribbon (with numeral 4), Army Service Ribbon, Overseas Service Ribbon (with numeral 3), Army Reserve Components Overseas Training Ribbon (with numeral 5), NATO non-article 5 Medal, Combat Infantry Badge, Expert Infantry Badge, Master Parachutist Badge, Air Assault Badge, Rams Head Device (Military Mountaineer), Expert Marksmanship Badge-Rifle, Panamanian-Pana Jungle Badge, Honduran Parachutist Badge, Canadian Forces Parachute Badge, German Army Marksmanship Badge Silver.

CSM Jenks is a professional firefighter. He serves as a Ladder Company Lieutenant. CSM Jenks is married to Molly Jenks, has two daughters and resides in New York.