A woman could camp overnight at 11000 feet among wolves in 1873.
Evidence
I could not sleep, but the night passed rapidly. I was anxious about the ascent, for gusts of ominous sound swept through the pines at intervals. Then wild animals howled, and ”Ring” was perturbed in spirit about them. Then it was strange to see the notorious desperado, a red-handed man, sleeping as quietly as innocence sleeps. But, above all, it was exciting to lie there, with no better shelter than a bower of pines, on a mountain 11,000 feet high, in the very heart of the Rocky Range, under twelve degrees of frost, hearing sounds of wolves, with shivering stars looking through the fragrant canopy, with arrowy pines for bed-posts, and for a night lamp the red flames of a camp-fire. — Isabella L. Bird, A Lady’s Life in the Rocky Mountains, 238