Summer green becomes autumn orange in the blink of an eye at Denali National Park in Alaska. Termination dust – what Alaskans call the high altitude snow that signals the end of summer – coats mountains and sprinkles onto valleys. The red leaves of blueberry bushes carpet the landscape and offer bears a last dessert before hibernation. It’s a feast for the eyes. Photo from a previous fall by Tim Rains, National Park Service.