Dr. Hann is born in Oklahoma City, Oklahoma to Roy W. and Irene Hann.
Dr. Hann receives a Bachelor of Science from the University of Oklahoma.
Dr. Hann receives a Master of Civil Engineering from the University of Oklahoma.
Dr. Hann serves on active duty as a Lieutenant in the United States Public Health Service.
Dr. Hann becomes an engineer at C.H. Guernsey and Associates in Oklahoma City.
Dr. Hann becomes an assistant professor of civil engineering at the University of South Carolina in Columbia, South Carolina.
Dr. Hann receives a Doctor of Philosophy from the University of Oklahoma.
Dr. Hann becomes an assistant professor of civil engineering in the Department of Environmental Engineering Division of Texas A&M University in College, Texas.
Dr. Hann is promoted to associate professor at Texas A&M University.
Dr. Hann’s Texas A&M Research Program on Houston Ship Channel Pollution is featured on national television on the first Earth Day.
Dr. Hann is appointed Head of the Environmental Engineering Program at Texas A&M University.
Dr. Hann receives the Life Paper Award from the American Society of Civil Engineers.
Dr. Hann becomes a full professor and research engineer at Texas A&M University.
Dr. Hann is dispatched by the commandment of the U.S. Coast Guard to study the impact of the Metula Oil Spill in the Straits of Magellan.
Dr. Hann is appointed director of the Sea Grant Program at Texas A&M University.
Dr. Hann is reappointed Head of the Environmental Engineering Program at Texas A&M University.
Dr. Hann receives the Palladium Medal from the National Audubon Society of the American Association of Engineering Societies.
Dr. Hann serves as owner and operator of Spring Valley Ranches.
Dr. Hann is appointed director of the Institute for Oil Spill Technology at the Texas A&M Engineering Experiment Station.
Dr. Hann retires from Texas A&M University to operate Hann Family Spring Valley Ranches and to pursue environmental engineering consulting.