645th Regional Support Group

645th Regional Support Group is a United States Army Reserve unit which controls a Combat Sustainment Support Battalion within Mississippi.

Units
The brigade is made up of the following units:
 * 645th Headquarters and Headquarters Detachment Regional Support Group
 * 406th Combat Sustainment Support Battalion
 * 406th Headquarters and Headquarters Company (CSS)
 * 180th Transportation Company (Medium Truck)(Cargo)
 * 182nd Transportation Company (Medium Truck)
 * 301st Transportation Company (Water Purification & Distribution)
 * 401st Transportation Company (Medium Truck)
 * 431st Transportation Company (Petrol P/L&TML OP)
 * 858th Transportation Detachment (Movement Control)
 * 919th Transportation Company (Cargo Transfer)
 * 952nd Transportation Company (Petrol P/L&TML OP)