Mike got his start in the horse business at an early age, learning from his father who raised remount horses for the Army. Mike started galloping race horses and on his 5th birthday he won three races at the Dodge City racetrack.  By the age of sixteen he was competing in amateur rodeos in the bareback riding, saddle bronc riding, bull riding, calf roping and steer wrestling, racking up many all-around titles.

Mike started judging local rodeos and horse shows. Monte Reger of Woodward, OK approached him and asked if he’d be interested in an AQHA Judges card.  That led to Mike proudly holding an AQHA judge’s card for over 35 years.  He was also an official judge with NSBA, NRHA, NCHA, APHA, PHBA, POA and APHC.  He has officiated at nearly every major stock show in the country, the NRHA Futurity, the Quarterama and the All American Quarter Horse Congress repeatedly.  He judged the first AQHYA World Show and returned to judge it two more times. He officiated the AQHA World Show five times and served as an AQHA liaison, judging overseas numerous times. Mike was honored to serve as a judge for the Miss Rodeo America pageant in Las Vegas.

In 1972, while judging a show near Glenwood Springs, Co, Mike spoke with Sissi Walker and happened to mention he would like to come to Arizona someday.  Soon afterwards he was asked to judge the AZ National’s Livestock Show Quarter Horse division.  In 1977 he judged the AZ Sun Country Circuit for the first time.  In 1979 he returned to the Sun Circuit as an exhibitor where he made War Machine a Supreme Champion. Mike relocated to Arizona thereafter.

Mike competed in Halter, Western Pleasure, roping events and Cutting.  At a time when horses were shown all day, Mike carved out a niche making AQHA Champions. Mike also had a successful breeding program with Smokey Poco Dude and Sonny Showcase.  Both were AQHA Champions, earning Superior awards in Halter, Heading and Heeling.  Their offspring continued their sires’ legacy, earning points in multiple events.  The 1st year of AQHA’s Incentive Fund, Clyde S Dale by Sonny Showcase received the largest payout check.

Mike served as a board member of AQHBA for many years and was elected President in 1995. Board members Chris Watson, Jin Dunn and Mike worked together as the founders of the Arizona Stallion Breeder’s Futurity (ASBF).  During the late 90’s, Equi-Stat ranked the ASBF as one of the top five paying futurities in the country.  Mike continued to give back to the industry by offering free clinics on a variety of topics; they always drew large crowds.

Mike also started colts for many local Thoroughbred trainers. Yearlings that sold at the annual  Keenland sales in Kentucky were often readied for the November ATBA sale.  One gelding arrived at the Drennan barn that Mike realized was special. After selling in the ATBA sale, he ran in the 2YO Futurity at Turf Paradise where he broke all U.S. speed records.  That horse, named by Mike, was Da Hoss.  He was a two time winner of the Breeders’ Cup Mile with 20 lifetime starts and earnings of almost $2 million.

Mike’s many years with the Quarter Horse breed has brought him full circle from racing as a small boy to a well-known trainer, breeder, AzQHA President and AQHA judge.

Mike Drennan was inducted into the AzQHA Hall of Fame in 2014.