The 191st Infantry Brigade was constituted on 24 June 1921 in the Organized Reserves as Headquarters and Headquarters Company, 191st Infantry Brigade, and assigned to the 96th Division.
It was organized in December 1921 at Portland, Oregon, and redesignated on 23 March 1925 as Headquarters and Headquarters Company, 191st Brigade, then redesignated on 24 August 1936 as Headquarters and Headquarters Company, 191st Infantry Brigade.
It was converted and redesignated on 6 April 1942 as the 96th Reconnaissance Troop (less 3rd Platoon), 96th Division (Headquarters and Headquarters Company, 192d Infantry Brigade, concurrently converted and redesignated as the 3rd Platoon, 96th Reconnaissance Troop, 96th Division).
The Troop was ordered into active military service on 15 August 1942 and reorganized at Camp Adair, Oregon, as the 96th Cavalry Reconnaissance Troop, an element of the 96th Infantry Division.
It was reorganized and redesignated on 16 August 1943 as the 96th Reconnaissance Troop, Mechanized, and then again reorganized and redesignated on 20 November 1945 as the 96th Mechanized Cavalry Reconnaissance Troop.
Following World War II service with the 96th Infantry Division in the Pacific, it was inactivated on 3 February 1946 at Camp Anza, California.

The unit was again activated on 20 January 1947 at Spokane, Washington. (
The Organized Reserves was redesignated 25 March 1948 as the Organized Reserve Corps; redesignated 9 July 1952 as the Army Reserve.)
It was reorganized and redesignated on 12 April 1949 as the 96th Reconnaissance Company and its location changed on 15 October 1951 to Salt Lake City, Utah.
As part of an overall force reduction in the Reserve, the unit was inactivated 1 June 1959 at Salt Lake City, Utah.
It was converted and redesignated (less 3rd Platoon) on 5 November 1962 as Headquarters and Headquarters Company, 191st Infantry Brigade, and relieved from assignment to the 96th Infantry Division (3rd Platoon, 96th Reconnaissance Company, concurrently redesignated as Headquarters and Headquarters Company, 192nd Infantry Brigade – hereafter separate lineage) and activated on 1 February 1963 at Helena, Montana, as the Army Reserve's only mechanized infantry brigade, with elements in four states.
The brigade consisted of these units:
 Headquarters & Headquarters Company, 191st Infantry Brigade, Helena, MT
 3rd Battalion, 38th Infantry, Provo, UT
 1st Battalion, 59th Infantry, Phoenix, AZ
 4th Battalion, 81st Armor, Salt Lake City, UT (attached for training)
 8th Battalion, 40th Armor, Tucson, AZ
 4th Battalion, 35th Artillery, Billings, MT
 4th Battalion, 11th Artillery, Salt Lake City, UT (attached for training)
 Troop D, 8th Cavalry, Ogden, UT
 191st Support Battalion, Great Falls, MT
 Co B (Medical), Pocatello, ID
 391st Engineer Company, Missoula, MT
The 191st held its first active duty training as a brigade at Fort Lewis, WA, in June 1963 and in May 1964 took part in Exercise DESERT STRIKE in the Mojave Desert.
Half of the brigade took part in the exercise while the other half participated in active duty training at Fort Irwin, CA.
According to an article in the March 1967 issue of The Army Reserve Magazine, "The 191st was to be the largest Army Reserve element in a combined operation that brought Active Army and Reserve Component troops together in the largest peacetime maneuver ever held in the United States.
Under the guidance of [Brigadier] General [John P.] Connor, the brigade worked around the clock to bring troops and equipment to the required state of readiness to make a good showing for the Army Reserve during the exercise".

The brigade returned to Fort Irwin for its 1965 active duty training, the first time all elements of the entire brigade attended training at the same location at the same time.
This was followed by extensive home station training in preparation for active duty training in 1966.
Such training continued into the following year as the brigade prepared for a field training exercise at Fort Irwin in June 1967.

The 191st Infantry Brigade was inactivated on 29 February 1968 at Hele
The 191st Infantry Brigade was constituted on 24 June 1921 in the Organized Reserves as Headquarters and Headquarters Company, 191st Infantry Brigade, and assigned to the 96th Division. It was organized in December 1921 at Portland, Oregon, and redesignated on 23 March 1925 as Headquarters and Headquarters Company, 191st Brigade, then redesignated on 24 August 1936 as Headquarters and Headquarters Company, 191st Infantry Brigade. It was converted and redesignated on 6 April 1942 as the 96th Reconnaissance Troop (less 3rd Platoon), 96th Division (Headquarters and Headquarters Company, 192d Infantry Brigade, concurrently converted and redesignated as the 3rd Platoon, 96th Reconnaissance Troop, 96th Division). The Troop was ordered into active military service on 15 August 1942 and reorganized at Camp Adair, Oregon, as the 96th Cavalry Reconnaissance Troop, an element of the 96th Infantry Division. It was reorganized and redesignated on 16 August 1943 as the 96th Reconnaissance Troop, Mechanized, and then again reorganized and redesignated on 20 November 1945 as the 96th Mechanized Cavalry Reconnaissance Troop. Following World War II service with the 96th Infantry Division in the Pacific, it was inactivated on 3 February 1946 at Camp Anza, California.
The unit was again activated on 20 January 1947 at Spokane, Washington. (The Organized Reserves was redesignated 25 March 1948 as the Organized Reserve Corps; redesignated 9 July 1952 as the Army Reserve.) It was reorganized and redesignated on 12 April 1949 as the 96th Reconnaissance Company and its location changed on 15 October 1951 to Salt Lake City, Utah. As part of an overall force reduction in the Reserve, the unit was inactivated 1 June 1959 at Salt Lake City, Utah. It was converted and redesignated (less 3rd Platoon) on 5 November 1962 as Headquarters and Headquarters Company, 191st Infantry Brigade, and relieved from assignment to the 96th Infantry Division (3rd Platoon, 96th Reconnaissance Company, concurrently redesignated as Headquarters and Headquarters Company, 192nd Infantry Brigade – hereafter separate lineage) and activated on 1 February 1963 at Helena, Montana, as the Army Reserve's only mechanized infantry brigade, with elements in four states. The brigade consisted of these units:
 Headquarters & Headquarters Company, 191st Infantry Brigade, Helena, MT
 3rd Battalion, 38th Infantry, Provo, UT
 1st Battalion, 59th Infantry, Phoenix, AZ
 4th Battalion, 81st Armor, Salt Lake City, UT (attached for training)
 8th Battalion, 40th Armor, Tucson, AZ
 4th Battalion, 35th Artillery, Billings, MT
 4th Battalion, 11th Artillery, Salt Lake City, UT (attached for training)
 Troop D, 8th Cavalry, Ogden, UT
 191st Support Battalion, Great Falls, MT
 Co B (Medical), Pocatello, ID
 391st Engineer Company, Missoula, MT
The 191st held its first active duty training as a brigade at Fort Lewis, WA, in June 1963 and in May 1964 took part in Exercise DESERT STRIKE in the Mojave Desert. Half of the brigade took part in the exercise while the other half participated in active duty training at Fort Irwin, CA. According to an article in the March 1967 issue of The Army Reserve Magazine, "The 191st was to be the largest Army Reserve element in a combined operation that brought Active Army and Reserve Component troops together in the largest peacetime maneuver ever held in the United States. Under the guidance of [Brigadier] General [John P.] Connor, the brigade worked around the clock to bring troops and equipment to the required state of readiness to make a good showing for the Army Reserve during the exercise".
The brigade returned to Fort Irwin for its 1965 active duty training, the first time all elements of the entire brigade attended training at the same location at the same time. This was followed by extensive home station training in preparation for active duty training in 1966. Such training continued into the following year as the brigade prepared for a field training exercise at Fort Irwin in June 1967.
The 191st Infantry Brigade was inactivated on 29 February 1968 at Hele
191st Infantry Brigade (United States)