Dierdorff started in Copper Mountain for the first time in the Nor-Am-Cup in January 2007 and finished 49th and 12th. In the 2008/09 season he won the overall standings of the Nor-Am Cup with one win and two second places. At the Snowboard Junior World Championships 2009 in Nagano he was eighth. He made his World Cup debut in September 2009 in Chapelco , which he finished in 42nd place. At the Winter X Games 2010 in Aspen , he came 16th. In the 2010/11 season he came in fifth with six top ten finishes and in the 2011/12 season with eight top ten finishes in fourth place in the overall standings of the Nor-Am Cup. At the Snowboard Junior World Championships 2011 in Chiesa in Valmalenco , like two years earlier, he finished eighth in snowboard cross. In the 2012/13 season he came in all ten participations in the Nor-Am-Cup in the top ten and thus achieved third place in the overall standings. At the Winter X Games 2014 in Aspen, he came 13th. In March 2014 in La Molina he finished fifth, his first top ten finish in the World Cup. In the 2014/15 season, he finished second and one at the Nor-Am-Cup in Copper Mountain and finally finished fifth in the overall standings. He also achieved 17th place in the Snowboard Cross World Cup. In the following season he finished 19th in the Snowboard Cross World Cup. His best World Cup result was sixth place in Feldberg . In March 2017 he finished second in the team competition in Veysonnaz together with Jonathan Cheever . At the beginning of the 2017/18 season he achieved his first podium finish in the World Cup singles with third place at Cerro Catedral . This was followed by six top ten finishes, including second place in Veysonnaz and seventh place in the snowboard cross world cup at the end of the season. At the 2018 Winter Olympics in Pyeongchang , he finished fifth in snowboard cross. The following year he won the home world championship in Park City , he won gold medals in both individual and team competitions.
Dierdorff has taken part in 50 world cup races so far. He achieved a top ten placement eleven times (as of December 25, 2019).
United States
World cup
