sorry for typing a short message.. got a call and had to run to a meeting.
anyway i'm back -
I looked from BWI - DEN using ITA's month long search for a 3 night stay... and then tried to see if it worked using travelocity's SKIMC150 (as mentioned above by hobo13) and it did.

I tried jan 16-jan 19... came to 243 - 150 = 93. I think the hotel was the best western in colorado springs.

If there are good deals to DEN from elsewhere it should work too. its great for the ski season.

the reason I listed it is because I remember there was a BWI-DEN thread a while back at $138.. this make that even sweeter if you really have to go to Den for 3 nights as you now get a hotel too and the total price actually drops.