This Is Grand Canyon Author:Stewart Aitchison By the 1890's, Grand Canyon was recognized as one of the America's most scenic wonders. Although Roosevelt established Grand Canyon National Monument by presidential proclamation, not until 1919 did Congress finally pass legislation to create Grand Canyon National Park. — Grand Canyon is one-half eighteen miles wide,a mile deep, 277 river... more » miles long- hardly begin to convey the awesome spectacle that is the Grand Canyon. the canyon is the epitome of the geologic forces at work on the Colorado Plateau.« less