Formation of the Grand Canyon

After viewing the Grand Canyon, I believe the canyon may have been formed through processes other than weathering resulting from the flow of the Colorado River. Travel guides and books usually say the canyon formed because of the flow of Colorado River over rocks that has been occurring for the last million (or billion) years. However, I believe more was involved. I would suggest that a large lake used to fill the entire Grand Canyon. Of course, the lake dried up over time, due to the heat and lack of precipitation in the area, maybe in the same way Lake Asal is drying up. Even the Colorado River itself would have dried up if the Glen Canyon Dam had not been created. The formations of the rocks and the width of the Canyon leave me with that impression. I have seen what lakes look like when water dries up, and I see a correlation between the gorge left from the lake and the Grand Canyon gorge. The formation of the Grand Canyon must have been a fascinating process that would be fascinating to see replicated.