Boulder County does dispatch for Louisville PD, they are the 400 units over the air. They can be heard on Boulder County Law on any of the simulcasted VHF repeaters (North, Central, and South) and their DTRS talkgroup (9100)
Louisville PD still uses VHF radios, so you might find that they sounds better on the VHF frequencies. For DTRS, Gunbarrel (3-054) is probably the best site that will have them 24/7. Other sites like Thorodin (1-005), Lookout (1-008), and Mead (1-012) have the talkgroup pretty often, but it can sometimes disappear for a few minutes.