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.
I am writing this review because the owner of Lugden, Mic, lost; "gave-away" my girlfriends suitcase when we were in Denver for a wedding the Sept. 15th, 2018 weekend. I do NOT want anyone to deal with what we went through. This seemed like a great idea to check our bags and walk around Denver for a few hours before having to catch the train to the airport, but after only checking our bag for an hour we went back by and my bag was sitting on the side of the van and her bag was completely gone! Again, out there for a wedding! She had shoes, jeweler, expensive purses and pictures of her and her deceased father that she takes everywhere with her to keep him close to her; but her bag was gone. He had no system to track, had zero clue who he had given it and could not call any of the previous people that he had recently given their bags back to them. He quickly ran off in side as I called to the police to get me his liability insurance policy and stated "Oh man I just remembered, her bag was really heavy right? Some guy came by and said it was his bag and there were books in it so I let him take it." WTF!!!!! How does someone take someone's checked bag and run off with it. To make matters worse because we had a plane to catch I called his insurance company the following Monday and his "Insurance Representative" informed me that Lugged Inc has lapsed on their insurance and has zero liability coverage for instances like this.
Instead of delivering a package to your home or business address, you can select an Amazon Locker location and pick up your package at a time that's convenient for you. Once your package is delivered to the Amazon Locker, you'll receive an e-mail notification with a unique pickup code that includes the address and opening times for your selected Locker location.