Larkin High School Coach
One of the pioneers of the girls athletic program at Larkin High School, O'Brien has been instrumental in the program's growth and success. As the Royals volleyball coach, at the midpoint of the 2005 season, she had a career record of 540-265-13. Her teams have won 5 Upstate Eight conference titles and 6 regional championships. Mary is one of only 18 volleyball coaches in the state to record 500 wins. A 1996 inductee of the Illinois Girls Coaches Association Hall of Fame, O'Brien served 24 years as an official starter for the IHSA Girls State Track and Field meet, an event she helped establish. She also served over 10 years as an IHSA track and field rules interpreter. O'Brien was the honorary referee at the state girls track and field finals in 2002. Mary was named official of the year by the National Federation of Interscholastic Officials Association in 1996, and she received the Meritorious Service Award from the Illinois Girls Coaches Association for track and field officiating in 1994.