Train
Those of you flying in and out of Denver (DIA) for the wedding can easily catch the A Train from Denver International Airport straight to Union Station in downtown Denver at any time of day. One way train tickets are $10 and the train leave aprox. Every 10 minutes except from 3am - 5am where it leaves every half hour.
Travel Note
If you plan on staying in town for the wedding, we do suggest looking into renting an Airbnb in downtown Denver. They are usually moderately well priced, comfortable and convenient for larger groups or families.