Colonel McLellan was commissioned a Second Lieutenant in August 1999 through the Officer Candidate Course (OCC) after graduating from the University of Minnesota-Duluth. Upon completion of The Basic School he attended Engineer Officer’s Basic Course and subsequently reported to Marine Wing Support Squadron 274, where he served as a platoon commander and Engineer Company Commander.
In 2002 he reported to 2d Combat Engineer Battalion where he served as Bravo Company Executive Officer. In February of 2003 he deployed in support of Operation Iraqi Freedom where he served as platoon commander in Task Force Tarawa. Upon returning from deployment he was assigned to Officer Candidates School (OCS). During his tour at OCS he served as a platoon commander, executive officer, and the Coordinator of Student Activities.
After graduating from the Expeditionary Warfare School in May 2007 he was assigned to 9th Engineer Support Battalion. In August of 2007 he deployed in support of Multi National Corps, Iraq and served as Route Clearance Coordinator. In July 2008 he received orders back to 2d CEB and was assigned as the commander of Company C. In September of 2009 he deployed with 2d CEB to Helmand Province as the Bn Ops O in support of the 2d Marine Expeditionary Brigade. In April of 2011 he deployed back to Helmand Province as the Bn XO in support of OEF 11.1. In January of 2012 he assumed the duties of 2d Marine Division Engineer.
In July of 2012 he transferred to Quantico, Virginia, to attend Marine Corps Command and Staff College where he graduated with Distinction and earned a Master’s Degree in Military Studies. In May of 2013 he was assigned to Combat Development Directorate, Combat Development and Integration Command where he served at the Counter Improvised Explosive Device Branch Head. In July of 2015 he reported to MCAS Cherry Point Facilities Directorate. From 2016 - 2018 he was assigned as the II MEF Engineer Officer. From July 2018 to June 2020 he commanded 2d Combat Engineer Battalion. Following Battalion command, he attended the U.S. Army War College where he was a Superior Graduate and earned a Master’s degree in Strategic Studies. In July of 2021 he reported to USNORTHCOM where he was assigned to the NCJ35 as the Maritime Branch Chief. After promotion to Colonel, he was reassigned to NORAD and USNORTHCOM J5 Strategy, Policy, and Plans Division where he served as a Division Chief, Chief of Staff, and J5 Deputy.
On 13 June 2024, he assumed his current duties as Commanding Officer of Combat Logistics Regiment 4.
Col McLellan’s personal awards include the Defense Superior Service Medal, Bronze Star Medal, Meritorious Service Medal with three gold stars, Joint Service Commendation Medal, Navy Commendation Medal, Joint Service Achievement Medal, Navy Achievement Medal with gold star, and the Combat Action Ribbon.