John Wesley Powell and ten other men loaded food and provisions into four boats in Green River, Wyoming on 24 May 1869. They followed the Green River to the Colorado and traveled through the Grand Canyon. One man left after the first month. Three more left in the third month. Those who remained finished the expedition on on 30 August. They were the first Europeans known to pass through the Grand Canyon. Powell was appointed the second director of the US Geological Survey. His scientific study of the southwestern United States convinced him that agriculture and deserts should not mix.(Wikipedia).
Terry Tempest Williams writes him a letter in The Hour of Land: A Personal Topography of America’s National Parks. This is an excerpt.
I have learned from your history Major Powell, that it is only through the power of our own encounters and explorations of the wild that we can cultivate hope because we have experienced both the awe and humility in nature. We can passionately enter in to the politics of place, even the realm of public policy and change it, if we dare to speak from the authority of our own residencies.