As part of the Army's Transformation Plan, the 3rd Brigade, 75th Division was redesignated as the 166th Aviation Brigade, under the command of Division West of the First Army. Its mission would be to train and mobilize aviation units of the Army's reserve and national guard components. It was to be the only brigade under the First Army that specialized in training for Army aviation units. It was activated 1 December 2006 as a reserve unit at Fort Riley. The brigade became a partner organization of the 1st Infantry Division, which was stationed at Fort Riley and could provide better support than the headquarters of First Army Division West, which was headquartered at Fort Carson, Colorado and maintained units all over the western United States. The brigade received a shoulder sleeve insignia on 13 June 2007, but it has not been authorized for wear due to First Army policy requiring its units to wear its SSI.