Yesterday as I was riding to the south of Franktown, CO I spied the below pictured landscape through the haze that dominated the distant mountains.
It reminded me of something I'd seen on either the History channel or the Discovery channel. How Colorado and the surrounding area, back in ancient times, was submerged under a huge inland sea which spanned about a third of what is now the USA.
The haze lent itself to helping you picture the far off landscape as it was as seabottom, with the visible flat-topped hills as old seamounts. Their flat-tops evidence of where the surface of the ancient sea had worn them down to the same level.
Hopefully, you can see the imagery I could see in the panoramic shot above. Picture the ancient sea's surface level with the top of the flat-topped hills and you'll get the idea.