• Constituted 6 June 1949 in the Organized Reserve Corps as Headquarters, 301st Military Intelligence Platoon.
• Activated 22 June 1949 at Austin, Texas
• Reorganized and redesignated 1 September 1950 as Headquarters, 301st Military Intelligence Battalion.
• Organized Reserve Corps redesignated 9 July 1952 as the Army Reserve.
• Battalion Inactivated 23 February 1953 at Austin, Texas
• Redesignated 16 September 1988 as Headquarters, Headquarters and Service Company, 301st Military Intelligence Battalion, and activated at Pasadena, Texas
  (organic elements concurrently constituted and activated)
• Battalion inactivated 15 September 1997 at Pasadena, Texas
• Activated 16 April 2005 with headquarters at Phoenix, Arizona^[1]

The 301st Military Intelligence Theater Support Battalion (301st MI TSB) is a MIRC-aligned Reserve Intelligence Battalion focused on providing highly trained intelligence Soldiers to facilitate and integrate into military units mobilized around the world. The 301st also trains and prepares for mobilization as a support battalion, focusing on the Pacific Theater under the 500th MI BDE.

301st currently provides training and specialization in the following Intelligence Sections: All-Source, Counter-Intelligence, Human Intelligence, Signals Intelligence, Geospatial Intelligence, and Technical Intelligence.

The 301st MI (TSB) is made up of four companies:

• Headquarters/Headquarters Detachment: Includes the primary Command Staff, Shops, Logistical and Mechanical support staff.
• Alpha Company: Consists primarily of All-Source, Geospatial, and Signals Intelligence Soldiers with the Emphasis of Fusion Intelligence.
• Bravo Company: Consists of All-Source, Geospatial, Counterintelligence, Signals, and Human Intelligence Soldiers.
• Charlie Company:

• Campaign Participation Credit: Alpha Company – Iraqi Service Streamer
• Decorations: none

• Unit Facebook Page
• http://www.inscom.army.mil/MSC/500MIB/301st.html
• http://www.history.army.mil/html/forcestruc/lineages/branches/mi/0301mibn.htm Archived 17 October 2012 at the Wayback Machine
• http://unitpages.military.com/unitpages/unit.do?id=104929^{[permanent dead link]}