Joe was a strong left-handed pitcher for Belleville Area College, Florida Southern University, McKendree College and the Mon-Clair League. He was drafted by the California Angels in 1980 while playing for BAC.

Mehallow pitched for the Sauget Wizards from 1987 to 1990, guiding his team to a Mon-Clair League championships in 1988 and 1989. The Wizards won the Metro East Night League championship in 1989 and also defeated Team USA. The solid southpaw was the starting pitcher against Team USA in 1989 and 1990. During his four-year stint with the Wizards, he won 57 games and received three ERA awards.

From 1984 to 1986, Mehallow pitched for the O’Fallon Merchants in the Mon-Clair League. That first year, he threw two no-hitters and pitched 35 scoreless innings. Two years later, he won the ERA title.

From 1979-93, Joe pitched for the Shiloh Blue Sox in the Mon-Clair League. During his 12 seasons in the Mon-Clair League, he won numerous MVP awards and played on nine all-star teams. In 1999, he was inducted into the Mon-Clair League Baseball Hall of Fame.

In high school, Mehallow starred at O’Fallon Township High School in the late 1970s. In 1979, he was named to the Mississippi Valley All-Conference team and Post-Dispatch All-Metro team. He was also a standout all-star pitcher for the O’Fallon American Legion team in 1978 and 1979. He later managed the team in 1983 and 1984.

Joe pitched for BAC in 1980 and 1981, Florida Southern College in 1982, and McKendree College in 1983.

Joe has been a member of the Greater St. Louis Amateur Baseball Hall of Fame Board of Directors since 2024.