Just the same, it's interesting that a simple experiment that could be done by creation scientists has not been done. Or if it has been done, they are afraid to publish the results. I can assure you that anyone who could demonstrate that the canyon could be formed in a thousand years or less would win great acclaim.
Well, there's the difficulty of building your own high-volume, high-speed river.... ;-) I suppose one could cite the development of high pressure water jet cutters as "proof"....
OTOH, the geological formation of the Columbia River basin and gorge suggests that you can get very significant geological features in a geologically short (thousands of years) time frame.
That said, I have to confess that I'm baffled by those folks who expend so much time and effort on this 6,000 year deal. Even as an article of religious faith, it just doesn't matter.