A sea of grass and plain. A valley of succulents. And then, seemingly out of nowhere, a mountain. And not just any mountain, not a rolling hill like those in the East, but a pointy-topped peak that shouts its difference from the surrounding terrain.

I’m still absorbing the sights of a week in the geological region known as Basin and Ridge, an area that takes in all of Nevada, much of Arizona and parts of Utah, New Mexico and California. It’s caused by tectonic plates sidling rather than colliding — or at least that’s what I can remember from Tom Clancy’s explanation (not Tom Clancy the novelist but Tom Clancy the Ramsey Canyon tour guide).

What matters now are the memories I have of those sky islands, the panoramic view off the ridge of Geronimo Pass in Coronado National Memorial or the piney forests of Mount Lemmon, forests made of trees that could not survive if they were plopped two thousand feet down at the same latitude.

It’s a lesson both expansive and tender, that we need what is immediately at hand but also what is far away, beyond the valley, where the next peak rises.