Wow! Is this DEEP!
"Several western canyons exceed the Black Canyon in overall size," Wallace Hansen wrote after studying the geology of the region for several years. "Some are longer, some are deeper, some are narrower, and a few have walls as steep. But no other canyon in North America combines its depth, narrowness, sheerness, and somber countenance of the black canyon of the Gunnison." And it is largely because of this unique combination of geologic features that the Black Canyon has been preserved in its wild state. (Text from National Park Service brochure)