Vacancy rates have been running less than 2% so finding a rental is going to be tough. Besides Craigslist and Backpage.com you may want to try Rent.com. Also if you are on Facebook try doing a search for Fort Collins rentals. If some one posted a rental and it is recent, you may be able to find one that way. I am working with several investors that are buying homes and renting them out but as of now they are fully rented. I will let them know and see if they may know someone else who may have a rental available.
BTW, Have you ever thought of buying instead of renting?
Let me know if I can help.
Remax Eagle Rock
Best of Luck,
ERA Herman Group