A 2024 graduate of Prairie Grove High School, Van Der Horn competed as a sprinter and distance runner for the Tigers at the 4A level. The Prairie Grove native earned three letters in track and field under head coaches Elder, Stelting, and Chandler, along with one letter in cross country under head coach Keith Boston.

The three-year letterwinner established himself as the fifth-fastest sprinter in program history in both the 100 meters (11.57) and 200 meters (24.35) during his senior season. Van Der Horn placed fifth in the 100 meters and seventh in the 200 meters at the conference meet in 2024.

Liam is the son of Christopher and Tessa Van Der Horn and hopes to major in kinesiology.