What declination marks the circumpolar limit for Fort Collins?

The circumpolar limit for a location is defined by the latitude of that location, which determines how far south one must go to see circumpolar stars. Fort Collins, Colorado, is located at approximately 40.6° N latitude. Therefore, the circumpolar limit for Fort Collins would be approximately 49.4° N declination, meaning stars with a declination greater than this value would remain above the horizon at all times.