I Marine Expeditionary Force
I MEF Logo
Ready. Engaged. Faithful.
Official U.S. Marine Corps Website


I MEF provides the Marine Corps a globally responsive, expeditionary, and fully scalable Marine Air-Ground Task Force (MAGTF), capable of generating, deploying, and employing ready forces and formations for crisis response, forward presence, major combat operations, and campaigns. 


7th Engineer Support Battalion Squad Competition
1st Marine Logistics Group
Sept. 10, 2021 | 0:56
7th Engineer Support Battalion Squad Competition
1st Marine Logistics Group
Sept. 10, 2021 | 0:56
Player Embed Code:
7th Engineer Support Battalion Squad Competition
7th Engineer Support Battalion Squad Competition
Mechanized Raid Course
Recon Ex: Working Hand in Hand
Super Squad 21
1st Medical Battalion En Route Care
1st LSB Conducts Parachute Operations
Why I Reenlisted: Sgt. Asia Schmitz
Chapter 3: Readiness
Covid-19 Q&A with CDR Gilstrap
Career Retention Commanding Generals Delegation of Authority
Introduction to Super Squad 21
Introduction to Super Squad 21
An EOTG Series: TRAP Course
U.S. Marines Conduct Air Delivery Operations
Vaccines Still Prevent The Spread Of COVID-19
Message to the Brigade of Midshipmen from 1st MARDIV
Covid Vaccine and the Second Shot
35XX First-Term Reenlistment Incentives
Range 800 Opening
Vaccines Can Protect Against the Delta Variant
Why I Reenlisted - Cpl. Smith
Super Squad 21 Teaser
1st Marine Division Band Performs "Waltzing Matilda"
I MIG Change of Command
How to Schedule a “Shot Ex”
Why We Chose To Vaccinate Our Children
1/5 Return to Water Operations Part 1: Crawl
1/5 Return to Water Operations Part 1: Crawl
Return to water operations
Vaccine Benefits: What's In It For Me?
En Route Care
Like Father, Like Son: Sgt. Trevon Wade
Like Father, Like Son: 1st Lt. Stefawn Payne
Like Father, Like Son: MGySgt (Ret.) Steve Payne
1st Tank Battalion Deactivation Ceremony
Bronze Star Awards Ceremony
I MEF/MCI West Navy Marine Corps Relief Society
2/11 Fitness Seminar
2/5 Fox Company conducts Stand-Down to Address Extremism in the Ranks
In Any Time and Place
Artemis Program
Artemis We Care
1st Marine Division 80th Anniversary
Artemis Program
Annie N. Graham: First African-American Woman to Join the Marine Corps
1stMARDIV CG receives COVID-19 Vaccine
V17: Sergeants Lead the Way
Photo Information

A Marine escorts an ambulatory HMMWV to a Shock Trauma Platoon during Exercise Steel Night’s mass casualty drill at Marine Corps Air Ground Combat Center Twentynine Palms, Calif., Dec. 12, 2015. The drill tested the 1st Marine Division’s ability to react to a large influx of injuries and wounds from battling the enemy. Steel Knight provides tough, realistic training for the Marines and sailors of 1st Marine Division.

Photo by Sgt. Justin Boling

Racing to save lives at Steel Knight

14 Dec 2015 | Sgt. Justin Boling Defense Media Activity

As the Marine Air-Ground Task Force moves toward its final objective, the ability to save lives is rehearsed during Exercise Steel Knight’s mass casualty drill, Dec. 12, 2015.

On the Front

Corpsmen attached to a unit can provide early triage and acute care to wounded and injured Marines in a combat zone. The Marines and corpsman of 5th Marine Regiment, 1st Marine Division, conducted the initial care of wounded casualties during the drill.

“It is important to develop the skills while we are at Steel Knight,” said Petty Officer First Class Joshua Vanderlay, a corpsman with 1st Marine Division, Division Surgeon’s Office, and the evaluator for the mass casualty drill for the team. “Knowing these corpsmen we send down range have the skills they need to take care of their Marines is critical.”

In the initial stage of the drill, the corpsmen and Marines performed basic first aid upon discovery of the wounded. The role-players provided a hyper-realistic training aid as they were real amputees with blood pumps and cut suits to replicate severed limbs.

“The contractors expose these corpsmen and Marines to wounds and injuries they may have never seen,” said Vanderlay. “It is huge boost to their confidence knowing they can deal with the stress of these very realistic patients.”

After finding the wounded, the first responder corpsmen assess and prepare the injured to be transported to the next echelon of care.

“It is imperative that the Marines develop these skills alongside their corpsmen,” said Vanderlay. “A corpsman is one person taking care 38 Marines or so, it helps if those Marines understand how to take care of wounded Marines.”

The drill tested the 1st Marine Division’s ability to react to a large influx of injuries and wounds from battling the enemy. As a mode of immediate transport, MV-22B Ospreys moved the most critical casualties through the cold morning air to a Shock Trauma Platoon. 

Shock Trauma Platoon

Upon arrival, casualties were initially searched and body armor removed. A team of corpsmen began to stabilize and assess each casualty. The medical personnel proceeded by providing aide and stabilizing patients.

“Today we are working with the division to stabilize and save the lives of wounded and injured Marines,” said Commander Herman Gonzalez, the Shock Trauma Platoon’s officer in charge. “Steel Knight is an exercise where we simulate a fight with an equivalent force, which leads to large number of wounded and injured.” 

The skills of these men and women keep the division’s ground combat in the fight.

“Since the exercise began, it has been long hours of coverage for numerous ranges and other events,” said Petty Officer Third Class Carl Cayetano, a hospital corpsman with Combat Logistics Regiment 1, 1st Marine Logistics Group. “I volunteered to come out to shock trauma to refresh some very important skills.”

Cayetano’s resiliency to remain focused on his responsibilities was test when fifteen minutes after his arrival on scene, one of the simulated casualties died. Shortly after, the platoon received a NATO 9- line message stating more casualties were on the way.

“The patients are coming in with gunshot wounds, shrapnel and burns, which can differ from what we experienced in Iraq and Afghanistan’s injuries from [improvised explosive devices],” said Gonzalez. “We stabilize and very carefully coordinate transportation to the next higher echelon of care. They are better equipped and handle the sustained care needed.”

Even in austere environments, the STP can provide care to approximately 50 casualties, making it a crucial asset during combat operations. 

“I wanted to participate in the mass casualty drill,” said Cayeteno. “It is a good refresher it has been quite a while since I saw all of the dynamics of saving lives. It reinforces the basics.”

For some Navy physicians, it was the first training on how to triage patients in a combat simulated environment, which leads to making difficult life or death decisions.

“Training during Steel Knight is a great way to get out of the hospital and be reminded of how to provide care during the fight,” said Gonzalez. “It is great they send us actual people, it keeps the training as realistic as possible. The instructors are very good at being able to simulate the numerous cases you may find while serving in the field.”

The skills rehearsed during this drill enabled Navy medical personnel and Marines to train realistically for potential future crises.

I MEF Leaders

George W. Smith Jr.
Commanding General, I Marine Expeditionary Force

Read Biography

Brig. Gen. Ryan S. “Chick” Rideout
Deputy Commanding General, I Marine Expeditionary Force

Brigadier General Rideout assumed duties as Deputy Commanding General, I Marine Expeditionary Force in July 2021. His previous assignment was serving as Director, Military Advisor Group, Combined Joint Task Force - Operation INHERENT RESOLVE based in Baghdad, Iraq from June of 2020 to June 2021. Fleet Marine Force assignments include: Commanding

Read Biography

Colonel Brian Rideout
Chief of Staff, I Marine Expeditionary Force

Colonel Rideout holds a baccalaureate degree in Psychology from Ohio Wesleyan University, a Master of Science in Information Technology Management from the Naval Postgraduate School, a Master of Military Studies from Marine Corps University and a Master of Arts in National Security and Strategic Studies from the Naval War College.  He is a graduate

Read Biography

Sgt. Maj. Terrence C. Whitcomb
Sergeant Major, I Marine Expeditionary Force

Sergeant Major Whitcomb began Marine Corps Recruit Training on 14 September 1993 at Marine Corps Recruit Depot, San Diego, California with Company C, 1st Recruit Training Battalion.  He was meritoriously promoted to Private First Class and graduated Recruit Training on 10 December 1993. Following graduation from Recruit Training, Private First

Read Biography

Command Master Chief

 Though a native of Montebello, California, Master Chief Ruiz calls Monte Vista, Colorado home.  He enlisted in the Navy in March 1991, reported to basic training at RTC Great Lakes, Illinois and completed Signalman “A” School at NTC Orlando, Florida.  After serving two tours as a collateral-duty Command Career Counselor in 2000 and 2003, he became

Read Biography