THAT NIGHT IN MY SLEEPING BAG, I endured the slow, painful thawing of my legs. We were still a day's trip upstream from our take-out, but there was no stopping us now. In the morning, we loaded the big raft and launched into the same river that had nearly killed me the night before. As we made our way down the Copper, I found myself glancing again and again at the frozen cargo. For obvious reasons, floating down a remote river with a buffalo skull onboard conjured the feeling of a bygone era.

Months later, after packing away meal after meal of delicious buffalo steaks and burgers, I'd mostly forgotten about the hardships of the trip. But I did spend a lot of time dreaming about the buffalo still up in the Wrangell–St. Elias. One afternoon, I phoned Becky Kelleyhouse, a biologist with the Alaska Department of Fish and Game, to find out how the animals were doing. Kelleyhouse grew up in Alaska, and her father was also a biologist for Fish and Game. She told me that only three other hunters out of the 24 permit holders had managed to get a buffalo. The future of the herd, said Kelleyhouse, is wide open. "The herd could expand and stay where it is," she said, "or it could split, and an offshoot herd might move away and establish itself in an unknown area. Or the herd could shrink. There's no way to know. We just wait and watch."

Later that evening, lying beneath my buffalo-hide comforter, my feet still faintly tingling from frost damage, I let myself imagine the wild American buffalo living as gloriously as it had in the past. Dozing off, I said a prayer I'd been repeating lately: Let the buffalo roam.