Quote Originally Posted by 21forme View Post
I can't help you with specifics, but don't be penny wise pound foolish. Rent a car, especially if you "want to see the sights."

As car rentals are more expensive at airports, take public transportation to an off-airport car rental site and go from there. Also, suggest you consider late Spring to Fall, as rental prices will be higher during ski season. Unless, of course, you want to make a few bucks by shoveling a roof or two.
Totally agree with this. Denver airport is the most expensive for car rentals in the USA (or close to it) but took train downtown, walked to a car rental place and saved $$. Colorado is a spectacular state that is best enjoyed by car. Thought, perhaps not in winter.