6th Marine Corps District Leaders


Commanding Officer, 6th Marine Corps District

Col. Lance J. Langfeldt

Colonel Langfeldt’s personal decorations include the Meritorious Service Medal with three Gold Stars, Navy and Marine Corps Commendation Medal with Combat Distinguishing Device and two Gold Stars, Navy and Marine Corps Achievement Medal with Gold Star, and the Combat Action Ribbon....

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Sergeant Major, 6th Marine Corps District

Sgt. Maj. William Banks III

Sergeant Major Banks enlisted in the Marine Corps in 1991 and completed recruit training at MCRD Parris Island, SC. Following recruit training, Private First Class Banks attended Marine Combat Training at Camp Geiger and the Marine Corps Combat Service Support Schools at Camp Johnson. PFC Banks...

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Sergeant Major, RS Jacksonville
Sgt. Maj. Sebastiano J. Siino

Sergeant Major Siino currently serves as the Sergeant Major/Senior Enlisted Advisor of the Recruiting Station Jacksonville.  He has performed in this capacity since June 2020.

Sergeant Major Siino was born in Orange, New Jersey in 1981 and enlisted in the Marine Corps in 1999.  He completed recruit training at 3rd Battalion India Co, MCRDPI in November 1999.

Upon completion of Marine Combat Training in January 2000, Private First Class Siino completed his military occupation specialty training at the Marine Corps Engineer School, Courthouse Bay, Camp Lejeune, NC as an 1141 Basic Electrician.

Private First Class Siino then reported to 9th Engineer Support Battalion, Okinawa, Japan for duty as an Electrician in May 2000.  While serving with 9th Engineer Support Battalion, Private First Class Siino was attached to the 31st MEU.  In September 2000 he was promoted to Lance Corporal.

In June of 2001, Lance Corporal Siino reported to Headquarters & Service Battalion, MCRDPI for duty as an Electrician.  In March of 2002 he was promoted to Corporal and held the billets of Training NCO, Night Crew Chief, and Platoon Sergeant.  In August 2003 he was promoted to Sergeant.

In September 2004, Sergeant Siino reported to Drill Instructor School MCRDPI.  Upon completion of Drill Instructor school he was assigned to Alpha Company, 1st Recruit Training Battalion.  During this tour he held the billets of Drill Instructor, Experienced Drill Instructor, Senior Drill Instructor, and 1st Battalion Drill Master.  He was meritoriously promoted to the rank of Staff Sergeant in January 2007.

In January 2008, Staff Sergeant Siino reported to Marine Wing Support Group 17, Okinawa, Japan for duty as an Electrician.  Staff Sergeant Siino initially served as the Safety Manager and then went on to serve as the PSD Company Gunnery Sergeant.  Staff Sergeant Siino then deployed to Pattya, Thailand for exercise Cobra Gold and was later activated for Operation Caring Response for Humanitarian Aid/Disaster Relief to the people of Myanmar.

In February 2009 Staff Sergeant Siino reported to 9th Engineer Support Battalion for duty as the Electrical Section Ops Chief.  Staff Sergeant Siino then served as the Company Gunnery Sergeant for H&S Company, 9th Engineer Support Battalion.

In February 2010 Staff Sergeant Siino executed orders to Marine Wing Support Squadron 374, 29 Palms, CA where he served as the Utilities SNCOIC.  In August 2010 Staff Sergeant Siino was attached to 1st Marine Regiment Camp Pendleton, CA to deploy as a Utilities Chief with Regimental Combat Team 1 to support Operation Enduring Freedom until July 2011. 

In November 2011 he was promoted to Gunnery Sergeant and executed orders to Navy Officer Candidate School, Officer Training Command, Newport, Rhode Island for duty as a Drill Instructor. While serving at Navy OCS, Gunnery Sergeant Siino was selected as the 2014 Naval Service Training Command Marine of the Year.

In June 2015 Gunnery Sergeant Siino was assigned to 7th Engineer Support Battalion in Camp Pendleton, CA where he served as the Utilities Platoon Operations Chief, Engineer Support Company.

In February 2016, First Sergeant Siino was frocked to his current rank and transferred to  

3rd Battalion, 5th Marines where he served as the Company First Sergeant for Kilo Company.  During his time with Kilo Company, he participated in the Marine Corps Warfighting Lab (MCWL) Sea Dragon experiment as well as deployed in support of the 31st Marine Expeditionary Unit.

First Sergeant Siino reported to 1st Marine Division Headquarters Battalion in February 2018 and was assigned as the Headquarters Company First Sergeant.  In November 2018 First Sergeant Siino was then assigned as the Communications Company First Sergeant.

In June 2020, Sergeant Major Siino assumed his current position as the Recruiting Station Jacksonville Sergeant Major.

Sergeant Major Siino is married to the former Ms. Elsa Zuluaga of Bogota, Colombia.  They were married in April 2012 and have two sons, Sebastiano and Matheo, and two daughters, Sophia and Isabella.

Sergeant Major Siino’s personal awards are the Bronze Star Medal, Meritorious Service Medal,  Navy & Marine Corps Commendation Medal with one gold star, and Navy & Marine Corps Achievement Medal with one gold star.
6th Marine Corps District