Sweeps of beargrass reach their climax now in the highest meadows. In dizzy succession wildflowers set seed. Fat and sluggish, marmots and ground squirrels disappear beneath the rocks. The golden eagle must search longer each day to find prey within its vast domain. Autumn lingers in the valleys and on the flanks of low ridges. The morning sun glints on hoarfrost, firing the yellow leaves of larch, aspen, birch, maple, and cottonwood, and shines on the blood-red berries of mountain-ash. Soon a night of killing frost will bring down the corpses of insects and spiders by the millions. The reptiles and amphibians, being cold-blooded animals, seem out of place in this long-wintered land. Unable to maintain body temperatures appreciably above their surroundings, they are the first to seek the protection of hibernation, collecting in dens or burying themselves beneath the ooze of pond bottoms. Songbirds gather and leave the valleys. The harsh cries of jays sound ominous now in the forest. Only the chickadees seem to ignore the long tree shadows; their ceaseless conversations carry through the leafless underbrush as they busily search for seed. Velvet has gone to bone, and in these final noon-warm days the rut runs through the land. It begins in the valleys in September with the joustings of deer and moose and the buglings of bull wapiti puncturing the forest silence. By November the higher meadows ring with the collisions of bighorn rams who compete for ewes by smashing together their massive, curled horns. On high slopes mountain goat billies posture and swagger; head to tail, they circle, threatening each other with dagger-like horns. From Flathead Lake, 100 stream kilometers to the south, kokanee salmon return to spawn in the clear, cold shallows of McDonald Creek. Gathering bald eagles surround the stream, again and again lifting vulnerable fish from pool and riffle. Perched by the hundreds along the stream course, their white heads and tails glistening against the dark trees, they stand out like lanterns strung for a banquet. Now the stinging wind comes down from the peaks and shuts the lakes. Life slows or sleeps. Ptarmigan, snowshoe hare, and longtail weasel, all wearing winter white, seek shelter and food in a silent land where spring and yellow lilies seem forever lost. ■ All life faces one ultimate challenge: to survive or not, to reproduce or fail, to bring one’s kind to tomorrow’s sun or vanish forever. This land is harsh. To survive in nature demands skill in the individual, excellence in the species, and a chance from the environment. [Illustration: The mink, a solitary predator associated with low-elevation watercourses, preys on anything it can catch and subdue.] Plant-and-Animal Communities Over Going-to-the-Sun Road