Rainbow Curve sits on tree line at 10,829 feet, where wind-flattened trees up to a thousand years old give way to open tundra. The lot is on the right going west, with four vault toilets and a sidewalk around it. The park recommends using it only when westbound, because eastbound drivers must cross oncoming traffic. Views take in Horseshoe Park, Deer Mountain and the Mummy Range. Clark's nutcrackers and golden-mantled ground squirrels work the overlook, and feeding them is illegal. It is chilly here even in midsummer, so a layer from the car is worth bringing. Afternoon storms are a real hazard from this point up, and in lightning the vehicle is the place to be.
See how small the trees are getting? That's tree line, and Rainbow Curve sits right on it, a quarter mile on, with its lot on the right side of the road. Pull in for the view or the vault toilets, and bring a layer from the car, because it's chilly up here even in the heart of summer. When you leave, turn right and keep climbing. The lot stands at ten thousand eight hundred and twenty-nine feet, almost half a mile higher than Horseshoe Park below. Those crooked trees, barely waist high, can be several hundred to a thousand years old. A seedling starts on the sheltered side of a rock, grows only as tall as the rock protects it, then stops climbing and goes sideways, rooting wherever a branch touches the ground. Any branch that rises above the shelter is usually destroyed. The Germans have the word for it, krummholz, crooked wood. Look for trees with branches on one side only. They're called banner trees, and they work like a compass, because the wind blows most often from the bare side, and the wind here comes from the west. The gray-and-black bird working the overlooks is likely a Clark's nutcracker. In fall it can cache up to thirty-three thousand seeds, carrying as many as ninety at a time in a pouch behind its tongue, and it can find them up to nine months later. The ones it misses plant limber pines in windy spots, so a bird's mistakes are planting these high forests. That striped beggar at the pullouts is probably a golden-mantled ground squirrel, bigger than a chipmunk, with no stripes on its head. Feeding either one is illegal, even grass or fruit. To the north is the Mummy Range. Market hunters and diseases from domestic sheep nearly finished the park's bighorn. By the nineteen fifties about a hundred and fifty were left, up in high country like that. Reintroductions helped bring them back to several hundred. From here up, the weather gives the orders. Lightning is common from June through September, with afternoon storms typical on the tundra, and if you can hear thunder you're likely within striking distance. If you hear it or see lightning, get back in your car. Don't walk out to an overlook and don't stand around a parking lot. If anyone has a headache, nausea or dizziness, don't push on to the top. Go back down. The last patchy forest gives out about a mile past Rainbow Curve, at about eleven thousand feet. After that there isn't a tree left between you and the sky.
Photo: NPS Photo / Helen Evans · Public domain