In my last post, I began a discussion of the Grand Canyon. I pointed out that although floods certainly can create layers of rock, a flood could not possibly have created the specific layers in the specific sequence found in the Grand Canyon. Now let’s consider the formation of the canyon itself. Young-earth creationists frequently compare the Grand Canyon to the Toutle River canyon, which was formed by a mudflow during the eruption of Mount St. Helens. They claim that water released after the flood by the breaking of a dam could have formed the Grand Canyon. However, these two canyons really are not at all alike. I can identify four different reasons why the method by which the Toutle River canyon was formed cannot explain the formation of the Grand Canyon.
The source of the material that produced the Toutle River canyon is evident. There is no evidence of a reservoir that could have provided the water necessary to quickly produce the Grand Canyon. Because the amount of sediment removed from the canyon has about the same volume as Lake Michigan, the reservoir that formed the canyon must have had a volume at least equal to several times that of all the Great Lakes combined. The prehistoric lakes that are invoked to explain the source of the water simply do not have sufficient volume to remove this much material.
The Toutle River canyon is most pronounced close to its source at Mount St. Helens and diminishes as it moves away from the mountain. This makes sense for a canyon that has as its cause a release of fluid from a particular source. The Grand Canyon, however, begins as a relatively small canyon in central Utah and becomes deeper and wider as it travels through the Colorado Plateau, until reaching its widest and deepest point hundreds of miles downstream in northern Arizona. This is not consistent with a catastrophic formation.
The Toutle River canyon is more or less straight, although it does make a few gentle turns as a result of the topography of the surrounding terrain. The Grand Canyon follows a meandering path, including a number of U turns, across an otherwise flat plateau. Water rushing with enough force to carve out a canyon does not follow a meandering path.
The Toutle River canyon is a single channel. The river in the Grand Canyon has numerous tributaries. These tributaries, where they join the Colorado River, are in “tributary canyons” as deep as the primary canyon. Water originating from a single source and rushing with enough force to create a canyon does not form tributary canyons.
So yes, canyons can be formed quickly. But the Grand Canyon could not have been formed quickly. The explanation more consistent with the physical evidence is that it was eroded over the course of many years through solid rock by a river following a meandering path across a relatively flat plateau.