Rear Admiral Callahan serves as the Commander of the Eighth Coast Guard District headquartered in New Orleans, and is responsible for U.S Coast Guard operations spanning 26 states, including the Gulf of Mexico coastline from Florida to Mexico, the adjacent offshore waters and outer continental shelf, as well as the inland waterways of the Mississippi, Ohio, Missouri, Illinois, and Tennessee River systems.
His previous Flag assignments include Assistant Commandant for Human Resources-Chief Human Capital Officer, Commander of the Coast Guard's Personnel Command, and Director of Reserve and Military Personnel Policy in Coast Guard Headquarters.
Rear Admiral Callahan is a Coast Guard aviator with over 30 years of military and civil fixed and rotary wing flight experience. He commanded two Coast Guard Air Stations, to include Air Station New Orleans, and the Coast Guard Aviation Training Center in Mobile, AL, which in 2005 served as the aviation operations and maintenance hub for the entire Hurricane Katrina response. His command became the largest operational air station in U.S. Coast Guard history, and played a key role in the Coast Guard's rescue of over 30,000 people in Mississippi and Louisiana. Over the span of his career he served in the Atlantic, Pacific, Great Lakes, and Gulf Coast theaters of operation including Alaska. He led Coast Guardsmen in executing all eleven of the Coast Guard's statutory missions, to include search and rescue and drug and alien migrant interdiction.
In addition to his operational tours of duty, Rear Admiral Callahan served as Coast Guard Liaison to NATO staff, Allied Forces Southern Europe, Naples, Italy, during the Bosnian conflict. He also served as Chief of Staff for the Ninth Coast Guard District, overseeing all Coast Guard activities in the eight state Great Lakes region, and served as Executive Assistant to the Commandant in Coast Guard Headquarters, Washington, D.C. A native of Littleton, Colorado, Rear Admiral Callahan graduated from the United States Coast Guard Academy in 1982 and holds a Bachelor of Science degree in Management, a Masters degree in National Security Studies, and is a 2005 distinguished graduate of the Air War College. He also completed the Harvard National Preparedness Leadership Initiative. Rear Admiral Callahan's personal awards include five Legion of Merit Medals, the Defense Meritorious Service Medal, two Meritorious Service Medals, four Coast Guard Commendation Medals, and various other service and campaign medals.