This has been a year for unusual socks. Case in point, I recently got to try a pre-production sample of "The Ultimate American Sock" which is made of something the manufacturer, United By Blue, is calling bison down.

Said "down" is actually the soft fluff from the inner coat of the American bison, and it's amazing stuff. It looks (and feels) about the same as the inner coat of the musk ox, A.K.A. qiviut up here in Alaska.

Both are lighter and warmer than wool, wick moisture, don't feel scratchy at all, and regulate temperature very well -- so if a winter day turns out unseasonably warm, your feet will stay comfortably cool.

United By Blue blends the bison fluff with American-sourced merino wool to make the sock yarn more manageable and, dare I say, more affordable. (The straight bison down sells for up to $300 per pound, because each animal produces just a few ounces per year -- but it's a renewable resource that can be humanely harvested over and over again.) The final product is 100 percent sourced, made and packaged in the United States.

A Win for Bison Down

I've had the test sample out in temperatures from 15 to 40 degrees Fahrenheit in uninsulated hiking boots. They feel like they'd still be nice and warm down to at least 5 degrees, and have been perfectly comfortable up to 40. They're at least as warm as pure merino socks of similar weight, and do a better job of regulating temperature when things warm up.

That said, these are definitely heavyweight socks -- great for winter, spring, fall and cool summers; maybe they'll come out with a super-thin version for wear in hotter weather. Heads up, these socks do run a little bit large so if you're on the cusp between two sizes, go for the smaller size. They won't shrink or felt, even when machine washed and dried.

The Ultimate American Sock is set to retail for $38 once it becomes available, which might sound like a crazy price for socks but is actually a good deal considering the materials and performance. The only real question is durability, but so far these show every sign of standing up well to extended wear.

I say hustle to get them at a discount via United By Blue's insanely popular Kickstarter campaign while you can. That works out to $25 per pair, or about the same as a pair of SmartWool socks. If I had to choose between the two, I'd go for the bison socks.
Disclosure: Review samples were provided by the manufacturer. For more information, please see our Ethics Policy.