1. Denali’s West Buttress.;Coombs,2006
2. Maxed out on Everest: how to fix the mess at the top of the world;Jenkins;Natl Geogr Mag,2013
3. Health screening on Aconcagua;Windsor;Wilderness Environ Med,2009
4. United States National Park Service. Historical SAR costs 1976-current. 2014.
5. Denali National Park Service. Average number of climbers on Mt. McKinley 1903–2012. Available at: http://www.nps.gov/dena/planyourvisit/upload/OVERALLCLIMBERSthru2012.pdf. Accessed February 11, 2014.