Aksar's post jolted me into the realization that things have changed since 1988, when I was on Denali. This prompted me to check the Denali NP website, especially the portion dealing with climbing within the park - http://www.nps.gov/dena/planyourvisit/upload/English-2-Ready-4.pdf . I found the introduction to this document, while written specifically for Alaska, has relevance to wild places and their users everywhere.

Indeed,things have changed in the last twenty-five years, especially the "special users fee" now collected for climbers of Denali and Foraker. In the NPS literature, this fee is not specifically described as a rescue fee, but does list the performance of many other services required by the volume of climbers.