Four Climate Zones in Ninety Miles

Here's the thing that makes this road remarkable, and I want you to watch for it all day: you are about to drive through the ecological equivalent of a trip from Canada to Mexico.

We start up here around eight thousand feet in cool alpine meadow and spruce-fir forest — country that feels like Colorado or even southern Canada. Over the next ninety miles we will descend to around three thousand five hundred feet at Clifton, into genuine Sonoran-edge desert with cactus and mesquite and summer heat that will slap you when you open the door.

In between, in order: spruce and fir, then aspen groves, then mixed conifer, then the great ponderosa pine belt, then pinyon and juniper, then oak and chaparral, then desert scrub. Each of those is a different world with different birds, different mammals, different flowers.

Biologists call these life zones, and the reason you can cross so many so fast is elevation — climbing a thousand feet is roughly equivalent, ecologically, to travelling three hundred miles north. We're going to drop four and a half thousand feet.

So the temperature outside your car may change by twenty-five or thirty degrees today. Keep a layer handy, and watch the trees change out the window.