Tinnon showed steady improvement on the field during his junior season with Division 1's Northern Colorado by earning a 3.68 ERA, a 6-2 record, and 1 save in 73.1 innings thrown over 15 appearances.
Last season, Tinnon was named to the Great West Academic All-Conference team after appearing in 21 games for the Bears. In 30.1 innings on the bump he recorded 14 strikeouts, posted a 1-2 record with one save, and ended the season with a 5.04 ERA. As a true freshman, Tinnon appeared in 14 games, spanning 28.2 innings, while struggling with an elbow injury much of the season.
Tinnon was a three-time letter winner while playing at Holy Family High School. As a senior he was named first-team All-State as well as being named the 3A Player of the Year. That same year he also helped lead his team to a State Championship. He is a native of Longmont, Colorado.