lots of places to top off the water tank, including nearly every National Forest campground, as well as many other places. Ask at any Tourist info or Chamber of Commerce, city parks, etc. With that said, I end up filling mine before I go ... should take my own advice and just have 5 gallons or so in there.
Be prepared for some ugly delays due to construction on I-70 at the Twin Tunnels just east of Idaho Springs. This weekend saw 30-60 minute delays westbound, and possible delays of 30 minutes either way due to blasting.
