There is a shelter about one third of the way up the volcano, but you're only allowed to stay there for one night. So, the typical plan, the one we did, is to hike to the shelter the first day, spend a short night there, then wake up at 2AM and hike six hours more to the summit and then all the way out of the park all on the second day. Starting the hike so early in the morning allowed us to walk up on hard snow rather than the soft mush that we encountered on the way down after the sun got high in the sky. If we had been able to hike up in the daylight, I think the three of us could've handled it without a guide since we all had some experience with crampons, but having to hike in the dark, it would've been very difficult and it's possible that we would've wandered into a crevasse. Also, we had beautiful weather, but if it had fogged over, we would've been in trouble if we'd been on our own. Hiking at night with the Milky Way stretching out before us, pointing directly at the summit, barely visible in the dark, was an awesome experience. As the sun began to rise, the horizon turned a brilliant bright red color. About three hours into the hike we were able to extinguish our head lamps and by the time we reached the summit, we were welcomed by a bright and cloudless morning. Although the sky was cloudless, there was low lying fog stacked along the mountains below that happened to represent the Argentina-Chile border. The Chilean side was totally fogged in while the Argentine side was completely clear.
I hate the idea of getting older and I don't advertise my birthday, but when I was filling out an insurance form to go on the Lanin hike, Richard's keen eye spotted the fact that my birthday would be the day we reached the summit. Mark and he decided to surprise me by secretly bringing a small bottle of champagne up the mountain and giving it to me on the summit. It was one of my most memorable birthdays.