the highway or road. While ACAVs did not have a cannon, the Sheridan's high recoil from its 152mm main gun negated it from firing excessive broadsides while moving down a road. Thus the most favored tanks for clearing highways with "thunder runs" on a daily basis, most often fell to the M48s of the 11th ACR and accompanying armor units. Arrival in country The Blackhorse Regiment arrived in Vũng Tàu, South Vietnam on 7 September 1966 and was commanded by Col. William W. Cobb. Operation Hickory (7–15 October 1966) produced the first enemy casualties inflicted by the 3rd Squadron and elements of the 919th Engineer Company in the vicinity of Phu Hoa. Blackhorse Base Camp Operation Atlanta was the code name for the establishment of Blackhorse Base Camp—the new home of the 11th Armored Cavalry Regiment in Vietnam. Blackhorse Base Camp was located approximately south of the village of Xuan Loc on Route 2 and approximately southeast of the village of Long Goia. Saigon is approximately to the west along Rt. 1. The operation began on 20 October and concluded on 3 November 1966. Stanton's Vietnam Order Of Battle lists the following locations for the 11th Armored Cavalry Regiment's headquarters in Vietnam: Bien Hoa September 1966 – November 1966 Long Binh December 1966 – February 1967 Blackhorse Base Camp/Xuan Loc March 1967 – January 1969 Lai Khê February 1969 Long Giao March 1969 – September 1969 Bien Hoa October 1969 – June 1970 Di An July 1970 – March 1971 Operation Cedar Falls From January until 18 May 1967, the regiment conducted three major search and destroy operations. These operations would later be known as reconnaissance in force (RIF) operations. The first of these operations commence on 8 January 1967 and was known as "Operation Cedar Falls". It continued until 24 January 1967. The 1st and 2nd Squadrons operated in the infamous "Iron Triangle" region near Ben Cat employing search and destroy tactics, screening and blocking, and security in attacks on successive objectives. Operation Junction City Operation Junction City I and II involved the 1st and 3rd Squadrons. It began on 18 February 1967 and ran through 15 April 1967. This operation took these squadrons to the headquarters of the Central Office South Vietnam (COSVN) believed to be located in Bình Dương Province with the objective of destroying this important headquarters. This joint mission conducted with the 1st Australian Task