It’s time for Frontier Airline’s annual Colorado Day sale! Through August 3rd, you can get one-way tickets starting at $49. The prices vary by distance, of course, so not all tickets are $49. Flights must be booked by August 3rd and available dates run through December 19th.
Also, they’re offering an additional 5% off domestic non-stop fares to and from Colorado with code COLORADO. (It appears that you can use this with the Colorado Day sale but I haven’t tried it.)
Hurry, flights tend to start selling out quickly with this sale! Go here to browse dates and order tickets.