Newspapers wrote that Edmundson "impressed with his graceful form and unfaltering determination." He is responsible for organizing the Idaho cross country team in 1908, which set the foundation for a team that would win nine Pacific Coast Conference titles. In 1908, Edmundson traveled to Stanford for the western U.S. Olympic trials, where he won the 800 meters and finished second in the 400 meters, but did not make the Olympic team. He later held the title of top half-miler in the country through 1912. Edmundson became the first Idahoan to compete in the Olympic Games in Stockholm in 1912. He finished seventh in the 800 meters and sixth in the 400 meters.