Written by Ice and Water

Now that the Swift River is running right beside us, let me show you how to read it — because this valley is a textbook, and once you can read a page of it you'll see the whole thing.

Start with the boulders. Look at the size of some of them sitting in and beside the river: rocks the size of delivery vans, sitting on top of everything else. No flood put those there. Those are glacial erratics, carried and dumped by a sheet of ice that sat over this whole region a mile thick, and left behind when it melted about twelve thousand years ago. Some of them are a different rock from the ledge they're resting on — they've been carried in from miles away.

Then look at the bedrock the river runs over: smooth, pink-gray, sculpted into curves and potholes. That's granite, and it's what gives this state its nickname. And those perfectly round holes you'll see drilled into the ledge at the gorges? Potholes — made by a single stone caught in a swirl of current, spinning in one place for centuries and grinding itself a bowl. Water and time and one patient rock.

And notice where the road runs: on a flat bench a little above the river, with the ground dropping off to the water. That bench is an old floodplain from when the meltwater rivers were vastly bigger than the stream you see now.

One more thing, and it matters. Rivers here still do this. In two thousand eleven a hurricane came up the coast and dumped a summer's worth of rain on these mountains in a day; the Swift and its neighbors took out road, bridges, and whole chunks of riverbank, and it took months to reopen. The valley you're admiring is not finished being made.