Mount Moran Turnout on the left faces the mountain's east side, where a black band of diabase 150 feet wide runs down the rock. Sedimentary rock caps the summit, the same layer that lies buried far beneath the valley, and Falling Ice Glacier can be seen on the mountain from this pullout. The turnout is accessible. Beyond it, the Potholes spread across the sagebrush on the right side of the road, stands of conifers growing in hollows left by buried ice, and Potholes Turnout, also on the right, explains them. Those who park here can also hear a Boone tale from the climbing history of these peaks. It takes a few minutes, and tapping play after turning off the car keeps it going.
Mount Moran is behind your left shoulder now, so don't crane for it. Its turnout is the next left, so wait for a gap in oncoming traffic, pull in, and it's another left back onto the road. Boone's got a tale here if you park, and if I cut out when you shut the car off, tap play. If you pull in, look for the black stripe down the face. It looks man-made. It's a dike of dark rock called diabase, a hundred and fifty feet wide. Roughly seven hundred and seventy-five million years ago this country stretched and cracked, and magma squirted into the cracks and cooled. You passed Jenny Lake a while back. Melt down the exposed part of that one stripe, and it would fill that lake three times over. If you're driving on, watch the right side in the next half mile for odd round stands of trees out in the sage. Those are the Potholes. Blocks of ice broke off the retreating glaciers and got buried in sediment, and when they melted they left hollows that trap moisture and dust, so trees could root. Other places call them kettles. If you've parked, look at the very top of the mountain. Sitting on the summit is a small island of Flathead Sandstone, about six thousand feet above the valley. That same layer is buried roughly twenty thousand feet under the valley floor, on the east side of the fault. One bed, split by more than twenty-five thousand feet. That's the park's own quick measure of this fault, and the valley keeps filling. An estimated four to seven thousand feet of debris has piled into the middle of it in the last two million years. From the turnout you can pick out Falling Ice, one of three glaciers here that are easy to see from a road. The mountain itself is named for the landscape painter Thomas Moran. Across Jackson Lake, in nineteen seventy-four, lightning lit the Waterfalls Canyon Fire, one of the earliest natural fires a national park let burn. It took thirty-seven hundred acres before autumn rain put it out, and while locals got up a petition demanding the park stop it, Time magazine praised the managers. Lodgepole pines count on fires like that. Their cones open when heated, and they drop their seed on the sunlit ground a fire leaves behind. If you've parked, stay put. Boone's got the tale of who stood on top of the Grand first.
Photo: Acroterion / Wikimedia Commons / "Mount Moran summit WY1" (cropped) · CC BY-SA 4.0