Sergeant Major Sundermier was born and raised in Spokane, Washington. She enlisted in January 1990 and underwent recruit training with November Company, 4th Recruit Training Battalion, Marine Corps Recruit Depot, Parris Island, S.C.
Following recruit training, Private Sundermier reported to the Motor Transport Mechanic Course, Camp Johnson, Camp Lejeune, North Carolina. Upon graduation, Private First Class Sundermier was assigned to Truck Company, Headquarters and Service Bn, 3rd Marine Division, Okinawa, Japan, as a Motor Transportation Mechanic. In December 1990, she was meritoriously promoted to Lance Corporal and earned the secondary MOS of 0411.
In August 1991, Lance Corporal Sundermier was transferred to Motor Transport Maintenance Company, 2nd Force Service Support Group and worked as a Maintenance Management Clerk.
In February 1992, Lance Corporal Sundermier then transferred to Training and Support Company, The Basic School, Marine Corps Base Quantico, where she served as the Maintenance Management Clerk. She was promoted to Corporal in June 1992.
Corporal Sundermier reenlisted in August 1994 and transitioned to the 0411 MOS, Maintenance Management Clerk. She was then transferred to the Maintenance Information Systems Office, Service Company, Headquarters and Service Battalion, Marine Corps Base Quantico.
In May 1995, she was promoted to Sergeant and transferred to 3rd Force Service Support Group, Okinawa, Japan, and was assigned to G-3, Headquarters Company, Headquarters and Service Battalion.
In August 1998, Sergeant Sundermier reported to Drill Instructor School, Marine Corps Recruit Depot, Parris Island. Upon graduation Sergeant Sundermier was assigned to Oscar Company. In January 1999, she was promoted to the grade of Staff Sergeant.
After a successful tour as a Drill Instructor, Staff Sergeant Sundermier was transferred to G-3, Headquarters and Service Battalion, 2nd Force Service support Group, Camp Lejeune. While she was stationed there, she deployed with the 24th Marine Expeditionary Unit, where she participated in operations in Kosovo, Djibouti, United Arab Emirates, Kuwait, and Iraq.
In October 2003 she was promoted to Gunnery Sergeant and was transferred to Okinawa, Japan, where she served as an instructor at the Staff Non-Commissioned Officers Academy.
Gunnery Sergeant Sundermier was transferred in June 2007 to Combat Logistics Battalion 8, Combat Logistics Regiment 2, 2nd Marine Logistics Group, where she was assigned as the Maintenance Management Officer and deployed to Fallujah, Iraq.
In April 2008, she was promoted to the grade of First Sergeant and was transferred to 8th Engineer Support Battalion as the Engineer Company First Sergeant. In May 2009, First Sergeant Sundermier deployed in support of combat operations in Helmand Province, Afghanistan.
In February 2010, First Sergeant Sundermier transferred to Marine Corps Recruit Depot, Parris Island, where she served as the Company First Sergeant for Oscar Company, Instructional Training Company, and Special Training Company.
In December 2012, Sergeant Major Sundermier became the Sergeant Major of Weapons Training Battalion, Marine Corps Installations East-Marine Corps Base, Camp Lejeune. In October 2013, she received orders to Headquarters and Support Battalion, Marine Corps Installations East-Marine Corps Base, Camp Lejeune.
Sergeant Major Sundermier’s personal awards include the Navy and Marine Corps Commendation Medal with four gold stars, Navy and Marine Corps Achievement Medal with one gold star, the Military Outstanding Volunteer Service Medal, and the Good Conduct Medal with one silver star.