Cadillac Desert. A history of how all the dams came to be.
The Emerald Mile. Things got pretty perilous at Glen Canyon Dam owing to it being too full at the wrong time of the year. In the midst of this, three guys decide to take advantage of flow levels we're unlikely to see again in our lifetimes to set an all time record for running the Grand Canyon. This is on my personal list of the greatest true stories ever told.
Down The River (or anything else by Edward Abbey, really). The titular essay is about a trip down the Colorado. Abbey was an ardent critic of Glen Canyon Dam for flooding Glen Canyon. Better known for writing The Monkey Wrench Gang and Desert Solitaire, but Down the River more specifically deals with the Colorado.