Ipinle Kolorado Writers Style Guide, Colorado State University, accessed January 19, 2009 http://www.denverpost.com/opinion/ci_5447358 Coloradoan or Coloradan "Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2000 to July 1, 2008". United States Census Bureau. Retrieved 2009-02-05.  "Elevations and Distances in the United States". U.S. Geological Survey. 2005-04-29. Retrieved 2007-10-19.  "National Geodetic Survey data sheet KL0637 for Mount Elbert". National Geodetic Survey. Retrieved 2007-10-19.