Well thank you all for the informative answers! I've checked with Carnival and it is $103 to take the trip to the White Pass Summit and back. Does that sound about right? Or for $199 they have the "touch of class" excursion that includes white glove service and all those extras.
I'd be interested in this as well because it goes into the wonderful territory of the Yukon so I can say I've visited one of our lovely territories =)
02/20/2011 Carnival Victory (San Juan - S Carib)
07/11/2010 Carnival Freedom (W Carib)
02/13/2010 Navigator of the Seas (W Carib)
05/14/2008 Carnival Spirit (Glacier Bay - Alaska)
11/12/2007 Carnival Freedom (US Inaugural - W Carib)
02/01/2007 Celebration (Bahamas)