We sometimes ski a few miles into a yurt after dark, mostly because it gets dark early in the winter and we can't leave until hubby is home from work. If there is a good moon reflecting off the snow, there is plenty of light. It's peaceful and beautiful. One night we did this when it was -15 F. Luckily it was only a few miles, and the yurt had a good wood stove and nice supply of firewood. One of my favorite memories now. I've backpacked in the dark a few times as well, again because we couldn't leave until late in the day. I've only done that on familiar trails, and not in grizzly country. Since most places around here are grizzly country, I don't do much night hiking, at least not on purpose. I got pretty spooked one fall evening in Yellowstone when we didn't finish the hike before dark. I was hiking along quickly, worrying about bears with senses on high alert, when a bunch of elk crashed through the trees just a few yards away. Scared the crap out of me.