Mount McKinley, or Denali as it is called by the native people of Alaska, is the highest mountain in North America and its summit is attempted by over 1000 climbers annually. Many factors affect the likelihood of achieving the summit of high peaks such as Denali: climber age, experience, weather, team characteristics, and many others. We analyzed the characteristics of mountaineers who gained the summit of Denali versus those who did not during the climbing seasons of 1990 to 2008. Of the 21,809 climbers who attempted to summit Denali during the study period, 11,297 (51.8%) achieved the summit. We found that male mountaineers were slightly more likely to attain the summit than females. Climbers older than 40 had a decreasing trend of summit success. Climbers from continents other than North America had better odds of achieving the summit. Our results help to better predict those who are more likely to achieve the summit of North America's highest peak. The information can be used by mountaineers during expedition planning so that team selection, route choice, and expedition style may be considered when evaluating chances for summit success. National Park Service administrative personnel and rescue staff may be able to identify climbing teams with a lower likelihood of summit success for proactive discussion or intervention prior to an expedition's departure for this unique and often very inhospitable mountain.