Carpenter has won the Pikes Peak Marathon on twelve occasions, the Vail Hill Climb eight times, the Imogene Pass Run six times, the Barr Trail Mountain Race, Everest SkyMarathon Tibet, and Aspen SkyMarathon five times each, and holds the course record for all of these events. He is also the record holder for running the fastest flat marathons run at altitude at both 14,000 and 17,000 feet. His success in the sport has been so extensive and dominant that he has been compared to Lance Armstrong, and described as "one of the greatest mountain runners of all time".