Well, not more than 150 yards from where I saw one earlier this fall, I heard, saw, and photographed a Northern Parula in west Fort Collins, near the Spring Creek bike trail at the end of Michener Drive. The bird was very active, and I was only able to get one useable photo (the dark, albeit faint, band on the throat rules out Tropical Parula, I'm thinking.).
Brad Biggerstaff
Fort Collins