National Parks preserve the most beautiful, most iconic, most scenic locations in the country. By the mid-1850s, Niagara Falls had become surrounded by ugly, commerical buildings and signage. This despoiling of nature's beauty raised people's awareness of the need to preserve the natural beauty of the land for the people and for future generations. Places like the Grand Canyon of the Yellowstone, Yosemite Valley, the Grand Canyon, the Rocky Mountains of Colorado, and Wyoming's Grand Teton mountain range have been set aside to preserve and protect their scenic beauty.
In the words of John Muir:
