The events are termed a "500 Year Flood." Some towns have been cut off for days due to the massive floods. At this point, hundreds of people are unaccounted for. They may be in their homes which have been cut off from access by washed out roads.
U.S. Army and National Guard troops have rescued 1,750 people cut off by washed-out roads in the mountain canyons of Boulder and Larimer counties.
This map may be of assistance to those traveling in Colorado.