Industry Tip: You can order lockers to match your school colors by having them painted in colorful two tones with the frame one color and the doors another. Another option is to match your combo locks with the color of your lockers; you can even have your school logo imprinted on your locks! The sky’s the limit with us so be creative in showing your school’s spirit and pride! Denver Locker Colorado
Rebecca, I remember a previous post that a visitor found storage at the bus station, so I called to see if still available, and it is. Lockers are $3 for the first hour and $1 per hour after that. It's difficult to find storage short term because of security/liability, esp. since 9/11. If you are staying at a hotel, they will often keep your luggage for you short term.
For longer term storage, there are many self storage units around the metro area. Not cheap, but then neither is paying extra baggage fees and lugging around extra stuff not needed for another leg of your trip, as it sounds like Terry might be doing. For example, I found "Downtown Denver Self Storage" with units starting at $45 a month. http://www.downtowndenverstorage.com/ Denver Locker