15

Any variation off interstate will take or add a day to enjoy overall..if you leave St Louis at 6am I doubt you will be in Denver at 8pm...but its possible.

16

For the record, the Google Maps drive time is 12 Hours and 8 Minutes. You can shave an hour or so off of that time by driving 5-9 mph over the speed limit. Unless the cops are running some sort of ticket writing contest, you're safe from them at that speed. You gain another hour going east to west because you cross from the central to the mountain time zone. That means that you could drive from St. Louis to Denver between 6 AM and 4 PM local time. With the Trapster App and a good radar/lidar detector you can probably cut an additional hour off the drive time. If you make more than two pit stops your slacking. Allowing 20 minutes per pit stop (pretty much the minimum time) and not getting caught by any construction delays means that you should pull into Denver in time for a nap before dinner. I'm certain that people can drive this route in less time but Denver by 3:45 PM is doing it the "right way" on I-70.