2022-2023: Redshirted both indoors and outdoors. Did run unattached at the Oliver Jackson Invitational – getting 8^th in the 110H.
2021-2022: Indoors – Competed in 4 meets indoors, finishing the season at the WAC championship, placed 6^th in the 60 hurdles with a PR time of 8.03, as well as running on the 5^th place 4x400 relay. Outdoors – competed in just 2 outdoor meet, before an injury finished his year. As the Wes Kittley Invitational, he finished 4^th in the 400H and 6^th in the 110H.

2020-2021: Indoors – ran in only 2 indoors meets, but place 4^th in the Corky Classic 60H and then placed 6^th in the 60 hurdles at the SLC championship and ran on the 9^th place 4x400 relay – this season was a redshirt year for all NCAA athletes due to the pandemic. Outdoors – running in 8 meets during the season, he placed 10^th in the 400 hurdles and 15^th in the 110 hurdles at the SLC championship, as well as running on the 9^th place 4x400 relay. Also placed 2^nd in the 110 hurdles at the ACU Last Chance 110H with a new PR of 14.21, in the Baylor Invitational in the 400H in a PR time of 53.90, and 5^th in the Aggie Invitational 110H.

2019-2020: Indoors – running in 4 meets indoors, Harrison placed 12^th in the SLC 60 hurdles. Outdoors – outdoor season cancelled due to pandemic, redshirt season for all NCAA athletes.

2018-2019: Indoors – In his first season competing for ACU, competed in 4 indoor meets, finishing the season by placing 15^th in the SLC 60 hurdles. Outdoors – ran in 8 meets for ACU outdoors, finishing 9th in the 110H and 15^th in the 400 hurdles at the SLC outdoor meet – he scored his first points at the conference level by running on the 6^th place 4x100 relay. Other highlights of the season included placing 4^th in both the 110H and 400H at the Baylor Invitational and 7^th at the Oliver Jackson Twilight 110H. In the summer following his freshman year, he also placed 14^th in the USATF U20 Championship 110H.

Before ACU: In 2018, as a HS senior, Harrison was 4^th in the 6A 110 hurdles at the Texas state meet and ranked #28 in the U.S. in the event.