In the FCC database I'm not finding any listing for Town & Country, or for ANY taxicab companies in Longmont. Taxi companies often use "DBA" names different from how they may be licensed.
Anyway, within a 20-mi radius of Longmont, I found these taxicab licenses:
Colorado Cab Company, PLAINVIEW, CO:
152.27
152.42
152.36
152.39
152.45
If they aren't using a trunked system or something like that, you might find more by doing a search between these limits:
152.27 - 152.45
157.53 - 157.71 (mobiles)
452.00 - 452.875
You're likely to find other types of businesses on many of those frequencies (especially the 452's), so your best bet might be to listen early mornings and after 5pm (go-to-work and going-home times), and weekends. Or late evenings when they get a lot of fares going from bar to bar.
