Wilderness Exchange is within walking distance of Union and they require you leave a bag with them when you go into the store, they may be willing to stash your bag for a few hours. No guarantee on that, but an option if you can't find anything else. They are only open 10am-6pm on Sundays, so you may have to wait around a bit or pick it up early depending on when you get there and will be leaving.
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/
The visually appealing and very durable Traditional Collection is our most widely distributed locker line. Offering the most value for typical locker applications, this collection is available in a full range of spacious sizes, from single- to six-tier configurations, as well as two-person, 16-person and wall-mounted. The addition of our new 2 person Z-Locker completes the Traditional collection.
3-Tier Locker compartments measure 19 in. high and 3-Tier Locker compartments measure 19 in. high and include two side hooks and number plates. Doors have top and bottom louvers for air ventilation. Recessed handle with finger-lift latch accommodates a standard padlock (not included). Welded steel construction with powder coat finish available in 17 colors. Overall size of locker ... More + Product Details Close