Born in Granite City, Dennis Ragan wrestled for IWCOA Hall of Fame Coach Red Schmitt at Granite City.

He compiled a varsity record of 50-7 and was captain of Granite City's undefeated team. He was a graduate of the class of 1973.

Dennis went on to Southern Illinois University-Edwardsville and wrestled for Larry Kristoff, a Distinguished Member of the National Wrestling Hall of Fame and also a member of the IWCOA Hall of Fame. A varsity letter-winner at SIU-E, Dennis placed first and third in the National AAU Masters Tournament.

He has coached at Carbondale for 38 years, posting a career dual meet record of 450-298. He has mentored 71 state qualifiers, 16 place-winners and three state champions. His teams have won 18 South 7 conference championships,13 regional championships, and one sectional title. His 1990 and 2015 teams qualified for the IHSA Dual Team State Tournament, finishing in the Top 8 in state and his 2009 team finished in the Top 16.

Both his daughter, Alli, and his son, Jared, qualified for the state tournament, becoming the first brother and sister to do so in the same year. Alli also became the first freshman girl to qualify for the state tournament. She has since qualified for eight world teams and has won two world silver medals. In 2020, she became the first female wrestler to be inducted into the National Wrestling Hall of Fame's Dan Gable Museum's Glen Brand Wrestling Hall of Fame of Iowa.

For the past nine summers, Dennis has been the head coach of the Illinois women's team. Dennis has been named Southern Illinois Coaches Association Coach of the Year 14 times.

In addition to his duties as head wrestling coach and teacher at Carbondale High School, Dennis has served as a football coach for 29 years.

He was inducted into the IWCOA Hall of Fame in 2012. He earned his Master's Degree from SIU-C in 1994.