Coach Timo Mostert has coached the Boys Cross Country Team at American Fork High School since 1998 after being at Murray (Ut.) High School for 10 years. His American Fork boys teams have competed at the State Championships every year he has coached, including 9 State Championships, 5 Runner-up trophies, 18 top 5 finishes, and 12 Region Championships. They have been ranked 14 of the past 16 years in the Southwest United States. His 2009 -2014, '16 teams all won the NXN Southwest Regionals,   placing 8th, 8th,  6th,  2nd,  7th, 5th, 2nd,  2nd, and 7th at Nike Cross Nationals with 9 All-America  honors  and a two-time Individual National Champion. At AFHS he has coached 45 XC and 68 Track All-State runners and 22 individual State Champions in Cross-Country and Track. In 2017 his boys set the National Record in the 4X1600m Relay.

Coach Mostert ran in his first track meet in 6th grade. He lettered 4 years in cross-country, and two years in track in high school and was a school record holder in the 3200m run. He was the first athlete at Parkland College (Champaign, Illinois) to compete in all 4 NJCAA National Championships (Cross-Country, Indoor Track, Outdoor Track, and Marathon) in the same year. After serving a mission to Ecuador for the Church of Jesus Christ of Latter-Day Saints, he ran cross-country and track for Brigham Young University. He has an A.S. in Secondary Education from Parkland College, a B.A. in Mathematics Education with a coaching minor from B.Y.U., and has done Graduate Studies in Mathematics at The University of Utah. He served 10 years on the Youth Committee and 3 years as Track-and-Field Committee Chair for the Utah Association of USA Track and Field, served as Vice-President of the Utah High School Track Coaches Association 2001-2019, and has taught at coaches clinics from California to Florida. He is a Masters level Certified Track and Field Official.  

He has been nominated twice (2012 and 2014) as "Coach of the Year" for the Utah Governor's State of Sport Awards. Coach Mostert  was recognized as "Teacher of the Year" at American Fork High School in 2006, as the "Utah Boys Cross Country Coach of the Year" in 2010 and 2018 by the NFHS,  as the "Distinguished Service Award 5A Coach of the Year" by the UHSAA for 2014-15,and the NHSCA "National Boys XC Coach of the Year" for 2016.