Terry, there are many storage unit places closer to the airport, but then of course you'd have to rent a car. DIA Self Storage, for example, is less than 10 miles away. You can google map Denver International Airport, then "search nearby" for "self storage units" if you think that's something you might want to do. http://www.coloradoselfstorage.com/
Lockers Denver 80293
No matter the class size or variety, school lockers are a must. Between the mix of classes, clubs, sports, and productions, there are a lot of books, uniforms, bags, homework, jackets, and everything in between. A locker is a home base for not only schoolwork, but a social spot for friends, the one place where students know that they and their belongings are secure. From hallway lockers to locker rooms, from preschool through college, we have every kind of locker for school that you could possibly need. Lockers Denver Colorado
In the States everybody is so concerned about liability.... We tried to store at Hertz (where we dropped the rental); no storage facility, no luck. Try a hotel; I tried several, if you are not a guest then they are not allowed. I tried the Information Centre; no luck, they had some bad experiences.... in the past. But they could not realy help me any further. One advise: try the Greyhound Bus Center. And yes! there you can store your luggage. Even my somewhat bigger suitcase. The lockers are somewhat small but high and deep enough. First 3 hours is to be paid for; $ 3 and after that a dollar for an extra hour.