I contacted Holland America regarding taking Discovery Cruise with points and
adding a Mckinley Railcar Tour at a cash cost. Holland America referred me to
http://www.graylinealaska.com (owned by Holland America) and there are precruise and post cruise options ($999 to $1200) for 6 day/5 night rail tours that go to Denali Natl Park. The rail car tours coincide with the Cruise sailings and are evidently the same itinerary on the same train that you would get if you booked the whole trip through Holland America crusie lines. Dean has said before that it is more cost effective to sell your points and pay for the cruise but it is nice to know that the option to use points and get the same trip at a lower out of pocket cost is available. Thanks to Dean, Kay, Carol and Minybear for pointing me in the right direction.
Bobh