In the 1800s, humans were busy scurrying across the globe prying into the blank spots on the map, why? Because, of course, they were
there. From the frozen poles of the Earth to its darkest jungles, we had a guy on it. Here in the United States, the transcontinental railroad had opened up the nation. But, despite nearly a century of poking around by native peoples, Spanish padres, men military, mountain and Mormon, there remained one big question mark over the terrain through which flowed the Green and the Colorado Rivers.
On then-existing maps of the area between Green River Wyoming and St. Thomas, Nevada, there might as well have been a label, in all-caps, bolded, italicized, underlined and with exclamation points: