No one knows for sure how the Grand Canyon was formed. Although, scientists have some very good guesses. Continental drift plays an major role in the formation of the Grand Canyon. As does water, ice ,and wind erosion and the Colorado river. When 2 of the oceanic continental plates collided, the sea floor (aka the tectonic plate) started to uplift. The conflict between the 2 plates formed the mountain range. The rocks that made up the mountain range are about 1.7 billion years old. These mountains have eroded away and sedimentary rock layers have formed over them. As the Colorado river, flowed through the gorge, it carved it out.
The dirt of the Grand Canyon is extremely dry due to the amount of sun it is exposed to. The plants that live in the Grand Canyon, have extremely short roots, and therefore, they are incapable of stopping erosion from occurring. When it rains in the Grand Canyon, it is a torrential downpour. The water can't get absorbed by the soil or plant, so it runs straight down the Grand Canyon into the Colorado River. This results in erosion and flash flooding. All of this combined makes the beautiful view of the Grand Canyon that we see today.