Sergeant Major Christina E. Hunts Horse-May enlisted in the Marine Corps in October 1996 and completed recruit training at MCRD Parris Island, South Carolina. After completing Marine Combat Training, she was assigned the Military Occupational Specialty of 2531, Field Radio Operator.
 
In March 1997, Private First Class Hunts Horse reported to 7th Communication Battalion, Okinawa, Japan and was subsequently promoted to the rank of Lance Corporal.
 
In August 1999, she was promoted to the rank of Corporal and was reassigned to 2d Force Service Support Group, Camp Lejeune, N.C., and was subsequently promoted to the rank of Sergeant. In July 2001, Sergeant Hunts Horse assumed the duties as Radio Chief in support of the 22nd Marine Expeditionary Unit.
 
In October 2003 Staff Sergeant Hunts Horse deployed in support of Operation Iraqi Freedom and Operation Enduring Freedom during which communication and supply services were provided to forces in theater. In October 2006 Staff Sergeant Hunts Horse-May volunteered for orders to Drill Instructor duty and reported to Drill Instructor School, MCRD Parris Island, S.C.
 
Staff Sergeant Hunts Horse-May was assigned to November Company, 4th Recruit Training Battalion, where she served as Drill Instructor, Senior Drill Instructor, Series Gunnery Sergeant, Battalion Operations Chief and Battalion Drill Master. She was promoted to Gunnery Sergeant in January 2007.
 
In January 2010 Gunnery Sergeant Hunts Horse-May reported to Combat Service Support Company, Instructor Battalion, The Basic School, Quantico, Virginia and also served as a Sergeant Instructor at Officer Candidates School. Selected to the rank of First Sergeant in November 2011, she was reassigned to Headquarters Company, The Basic School.
 
In September of 2012 First Sergeant Hunts Horse-May reported for duty to 9th Communication Battalion, I MHG, Camp Pendleton, California and assumed the duties of Company First Sergeant for Company B and Company C. During her tenure, Company B deployed to the Helmand Province, Afghanistan in support of retrograde missions while simultaneously providing reliable communications support throughout the 12-month deployment.
 
In May of 2016 First Sergeant Hunts Horse-May reported for duty to Wounded Warrior Battalion (West) to stand up the newly formed Company D. In November of 2017 First Sergeant Hunts Horse-May was selected to the rank of Sergeant Major. 
 
In March of 2018 Sergeant Major Hunts Horse-May was assigned as the Station Sergeant Major for Recruiting Station Los Angeles.  
 
In September 2020 Sergeant Major Hunts Horse-May was assigned to Marine Aviation Logistics Squadron-36 as the Squadron Sergeant Major.
 
In March 2022 Sergeant Major Hunts Horse-May was issued orders to 1st Transportation Battalion, Combat Logistics Regiment 1, as the Battalion Sergeant Major.
 
In March 2023 Sergeant Major Hunts Horse-May was issued orders to 1st Supply Battalion, were she serves in her current billet as the Battalion Sergeant Major.
 
Sergeant Major Hunts Horse-May's awards include the Meritorious Service Medal with three gold stars, the Navy and Marine Corps Commendation Medal with three gold stars, and the Navy and Marine Corps Achievement Medal with two gold stars.