I haven't had any experience with Beaver Creek, but it looks like any agency that covers Beaver Creek is on the Colorado's DTRS (Digital Trunked Radio System). You'll need a APCO 25 capable scanner, or you won't be able to hear anything.
If you do have an APCO 25 scanner, you should consult the database (
State of Colorado DTRS Trunking System, Statewide, Multi-State - Scanner Frequencies) for more information. Looks like Site 235 (Beaver Creek) and Site 250 (Lower Dowd) would be your best options for frequencies to program in. As for talkgroups, I don't really have much for you besides saying that I know you'll want Eagle River Fire, Eagle Ambulance, and possibly Avon PD.
Hope that helps you a little, I'm sure someone else more knowledgeable will be able to key in with more information.
Edit: I just realized that you're looking for a different department altogether. I don't know any of their frequencies. Sorry I couldn't help you a little more.
Edit2: Seeing that the Beaver Creek Public Safety Department is part of the Beaver Creek Metro District, I did some searching on the database. You might want to plug in some of these frequencies and see if any of these are what you're looking for.
Colorado Scanner Frequencies and Radio Frequency Reference