[dirtboy]

And that would have required water and a active drainage basin over a very long period of time plus a period of time for the present formation to rise above the surrounding area.

Given the uplift has been going on for about 1.5 to 2 million years, I'd say there has been plenty of time for such. Heck, the Rockies were buried up to their chins in debris and were exhumed over the last ten million years as the region rose about a mile in elevation.

[count-your-change]

But I suggest that the area looks from the air more like the results of one piece of plate pressing into another, i.e., the long sw to nw ridges.

That, if true, would predate the formation of the lakes as a source of water.

Still a great many questions remain. How fast water can erode the stone, how long water has flowed through this particular gorge and a constnat source of water.

I wouldn’t preclude anything just yet.