Forward Operating Base Kalsu

After Operation Iraqi Freedom 1 (OIF1), FOB Kalsu was occupied by Company A, 1st Battalion, 152nd Infantry Regiment, Indiana Army National Guard from October 2003 to January 2004 acting as a quick reaction force (QRF) for Main Supply Route (MSR) Tampa and conducting combat patrols.

The base was then occupied by B Co, 2-505th Infantry Regiment, 82nd Airborne Division from January 2004 to May 2004 effectively conducting combat patrols and acting as the QRF for MSR Tampa.

It was then occupied by the 118th MP CO (ABN), 16th MP BDE (ABN) along with the attached A CO 1-185th Armor Regiment (Provisional Infantry), and the Mortar & Scout platoons of HHC 1-185th Armor, 81st Heavy Brigade Combat Team of the California Army National Guard from March 2004 to February 2005 conducting combat patrols and acting as a QRF for MSR Tampa. On May 25, 2004, Specialist Daniel P. Unger, Specialist Alan N. Bean Jr., and Sgt. Kevin F. Sheehan, were killed, along with numerous others wounded, during what some have described as one of the worst mortar attacks in the history of the war up until that time. [3] The new dining facility later built at FOB Kalsu was named "Unger Hall" in honor of Specialist Unger, who put the lives of several Iraqi workers he was guarding ahead of his own to ensure they were safely inside the bunker during the main attack, and was posthumously awarded the Bronze Star Medal with Valor for his heroism.[4]

In July 2004 the 24th Marine Expeditionary Unit (MEU), 1st Marine Division, assumed command of FOB Kalsu using it as a command post for operations in the Anbar Province and the areas south of Baghdad to northern part of Babil and then subsequently the assault on Fallujah in November 2004. One month after the Marines took over command of FOB Kalsu the mortar and rocket attacks dramatically decreased. In February 2005 155th Heavy Brigade Combat Team of the Mississippi Army National Guard assumed command through January 2006. 2d Squadron, 11th Armored Cavalry Regiment from FT Irwin, Ca, was attached to the 155th HBCT during this period. In November 2005 the 155th was visited by Mississippi Governor Haley Barbour.[5]

From November 2005 to November 2006, FOB Kalsu was occupied by 2nd Brigade Combat Team, 4th Infantry Division (United States) Led by Lt Col Howard and CSM Cervantes. Units of 2BCT/4ID that occupied FOB Kalsu included 2d Battalion 8th Infantry Regiment, 2d Special Troops Battalion, and 2d Brigade Headquarters Company. Prior to the end of the deployment 2d BCT's 3rd Battalion, 16th Field Artillery Regiment and 204th Brigade Support Battalion had also moved to FOB Kalsu.

Second Lieutenant Emily Perez was stationed at FOB Kalsu in September 2006 when, while leading a convoy conducting re-supply operations in the vicinity of Al-Najaf, her HMMWV hit an IED, making her the first female West Point graduate to be killed in Iraq.[6] The COS Troop Medical Clinic was named in her honor.[7]

From October 2006 to December 2007, FOB Kalsu was occupied by the 4th Brigade Combat Team (Airborne), 25th Infantry Division headquartered at Fort Richardson in Anchorage, Alaska.

In October 2007, the 4th BCT of the 3rd Infantry Division took control of the FOB.[8] In December 2008, the Vanguard Brigade transferred authority to the 172nd Infantry Brigade Combat Team (Blackhawk Brigade) headquartered at Grafenwoehr, Germany.[9]

From September 2009 to September 2010, COS Kalsu was manned by elements of 3HBCT (Heavy Brigade Combat Team), 3rd Infantry Division.

From September 23, 2010, and continuing until August 2011, COS Kalsu was occupied by the 3d Armored Cavalry Regiment, as well as their subordinate units, 1st Squadron 3rd Armored Cavalry Regiment (Tiger Squadron) and Regimental Support Squadron (Muleskinner Squadron) in support of Operation New Dawn.[10]

In July 2011 the 2nd Battalion, 5th Cavalry Regiment (2-5 CAV) and the 115th Brigade Support Battalion of the 1st Brigade Combat Team, 1st Cavalry Division replaced 3rd Armored Cavalry Regiment in support of Operation New Dawn.