The Gulf Coast HIDTA consists of 25 counties/parishes in Alabama, Arkansas, Louisiana, and Mississippi.

The HIDTA counties in Alabama are Baldwin, Jefferson, Madison, Mobile, Montgomery, and Morgan.

The HIDTA counties in Arkansas are Benton, Jefferson, Pulaski, and Washington.

The HIDTA counties in Louisiana are Bossier Parish, Caddo Parish, Calcasieu Parish, East Baton Rouge Parish, Jefferson Parish, Lafayette Parish, Orleans Parish, and Ouachita Parish.

The HIDTA counties in Mississippi are Hancock, Harrison, Hinds, Jackson, Lafayette, Madison, and Rankin.

Atlanta, Georgia; New Orleans, Louisiana; and Memphis and Nashville, Tennessee are major cities with over 250,000 people. Birmingham, Huntsville, Mobile, and Montgomery, Alabama; Little Rock, Arkansas; Tallahassee, Florida; Baton Rouge, Lafayette, Metairie, and Shreveport, Louisiana; Jackson, Mississippi; Chattanooga, Clarksville, and Knoxville, Tennessee; and Beaumont, Texas are major cities with 100,000-249,999 people. Cities with less than 100,000 people are Tuscaloosa, Alabama; Fort Smith, Arkansas; and Albany, Roswell, and Sandy Springs, Georgia. Other cities of interest are Pine Bluff and Texarkana, Arkansas; and Biloxi and Oxford, Mississippi.

The international airports are Birmingham International and Huntsville International in Alabama; Alexandria International and New Orleans International in Louisiana; Jackson International in Mississippi; and Memphis International in Tennessee.

There are major seaports at Mobile, Alabama; Metairie and New Orleans, Louisiana; and Biloxi, Mississippi.

The interstates within this region are I-10, I-12, I-20, I-30, I-40, I-49, I-55, I-59, I-65, I-75, I-85, and I-185.