dear Cainie Thanks for your learned input and great how the rockies were formed data reference sheet. I am or maybe very Wrong! but inmy life till YOU go down inside a tunnel and "READ" the Earth, and what in fact is is front of YOUR eyes YE had best Question, What WE have been taught! YEP in many ways the How the Rockies were Formed is OK. however have a real big problem with regional Uplift ?? YEP Most of the very early Rockies did in fact erode into a flat plain and I think today makes up most of the "Denver Basin"" east of Denver?? I stand to be corrected on this statement, Just too much "junk" handed down over the yrers from USGS an d Colo School of mines that does NOT match with reality walking over and into too many tunnels over the years past> I do not wish to start any "flames" here!!! been ther done that and ITS scary to see that wall of fire coming towards YOU ! and that was a Coal Mine!!! So Sir with all due respect until YOU have been underground and I suspect YOU may have been there, rememember the lessons YOU were taught by the folk that took You Inside? those tunnels knew MOM Nature, what the smells meant and why the water on the floor,spent so much time "rotting" out the rails? WE are only a Visitor and the tunneles wiil fall down after WE leave. as so many have now collapsed! Just some thoughts Here been there done that, So MUCH WE have Yet to Learn from Scorpio