For a very long time, the only Coloradan team you could expect to see in the U.S. Open Cup was the Colorado Rapids. Since MLS teams didn't even get an autoberth for a long while, even that wasn't always a guarantee, and the state of Colorado went unrepresented a few times.
Now, with MLS teams getting an automatic berth and a couple of minor league sides in our state getting some stability, we're going to see three Coloradan teams in the 2013 version of the Cup tournament. I don't know if that's a record -- the competition is 100 years old, after all -- but that's certainly a decent number for a state that hasn't always been exactly soccer hungry.
Colorado Rovers are the lowest tiered team in the tournament, being the only entrant from the USSSA, winning an 18-team tournament for the privileged to be entered in. They will play one of the first games of the tournament, facing off against the Georgia Revolution of the NPSL on May 7th in Denver. (I assume that there will be a rather large batch of Rapids fans at the game, cheering the lower league boys on!)
A few steps up on the pyramid, the Real Colorado Foxes will be in their third straight Open Cup run. They got a win the first time around, but fell to K.C. Athletics FC in the first round of last season's competition. They will enter the first round of competition, which starts on May 14th.
And, of course, our Colorado Rapids will take one of the automatic berths for United States-based MLS teams in the third round of competition, starting on May 28th. They'll look to build on a decent run last season that saw them defeat the Tampa Bay Rowdies before falling to the eventual champions, Sporting Kansas City.