A multi-sport student athlete, Hoover competed in basketball, field hockey, bowling, golf and swimming - but her major accomplishments at the UofA came in tennis. As a freshman she held the UofA singles championship in 1945 and did it again in 1947. In 1946 she won the national junior doubles championship. That same year she held six other titles from tournaments in the East and Southwest. Mary was appointed to the National Junior Wightman Cup squad in 1946 and ranked first in doubles in the U.S. and seventh in singles. She also won the national junior girls tennis doubles championship. In 1947 she was named rodeo queen. When she returned to Texas she became an avid golfer. In 1947, Mary was inducted in to the El Paso Athletics Hall of Fame (only third woman to do so at the time) and the El Paso Golf Hall of Fame in 1985.