1997
"Boat wakes have replaced the raging rapids of the Colorado."
PBS TV program,  1997
1946
A natural menace becomes a national resource
subtitle of a Bureau of Reclamation report on Glen Canyon, 1946.
1963
The wild, red, outlaw river,
Tamed.
Now flowing clean and blue,
Unmaimed.
Lake Powell, Jewel of the Colorado
Keturah Pennington near Oil Seep Bar
The U. S. Bureau of Reclamation wished to build a dam that would flood Glen Canyon.  Arguments favorable to building the dam were selected and touted.  Arguments against were ignored, even suppressed.  Though the Colorado River in Glen Canyon was among the gentlest of all rivers and the experience of floating that river one of the most sublime, the Bureau invoked the fierce reputation of the Colorado.  "Wild, red outlaw river."  "Natural menace."  Not one "rapid" in Glen was more than an insignificant "riffle" to an experienced whitewater runner.  Even though the reservoir would result in a substantial reduction of agricultural water because of evaporation, seepage, and "subtle" statistical effects of cyclical rainfall, they invoked the reputation of dams and reservoirs as sources of agricultural water.  Such is the "logic" of the propagandist, always selecting, always slanting, always spinning.

         The Bureau had been sending out strong signals 
        for our "crap detectors" to intercept.  See "CD."
You, too, can You have an attractive hypothesis...
Here is what narrator Ted Hallock spoke about Lake Powell's effect on Glen Canyon, in a 1997 PBS documentary  (showing truly raging rapids—not in Glen—everywhere the narration suggests):

"It's a different kind of wild West on Lake Powell.  Boat wakes have replaced the raging rapids of the Colorado, a river first explored over a century ago by John Weseley Powell.  Although Lake Powell is named for him, he might not have been delighted to see what happened to the 186 miles of the exhilarating, untamed river he explored just over a century earlier...

"[Powell's journey became] the adventure of the century.  The anticipated 300-mile journey turned into a thousand miles of hardship...  For 300 of those thousand miles, they ran the gentle Green River.  Then, rounding the Island in the Sky mesa in what is now Canyonlands National Park, they reached the confluence of the Green and Colorado Rivers.  Next, a wild ride through Cataract Canyon, and finally, arriving at Marble Canyon where the walls begin to close in on them, the gateway to one of the greatest natural wonders on Earth."

Chris Suczek in Four Mile Rapid

 

 

 
And what we discovered:

Until 1962, between the confluence of the Green and Colorado Rivers and the beginning of Marble Gorge at Lee's Ferry lay 170 miles of one of the greatest natural wonders on Earth: Glen Canyon, the gentlest of rivers with as exquisite a beauty as ever experienced by mankind.

Go to Glen