Nearly all Colorado Trail travelers carry the CT Databook. Mile by mile it describes the route including the water sources that are so essential to replenish supply and stay hydrated. You’ll see people referring to it often.
As the Trail has changed over the years, so has the CT Databook. It is now in Edition 7 which is the first-ever that’s waterproof and, each edition has undergone major refinement. You can read about and buy it via the new Colorado Trail Foundation website, here:
Though this newest, current edition of the pocket guide is in color with water symbols and handy maps, the book wasn’t always this way.
The 1st Edition CT Databook was published in 1999.