As we passed 19,000' elevation I paused to take pictures and a video of the imminent sunrise. Panning from east to west (left to right in the picture facing south), the transition from light to dark was dramatic. It was a marvelous feeling to be on the boundary between day and night. Of course, the video I took does not capture the dramatic transition since the camera attempted to compensate for the lower light as I panned to the west (17:00 in the video).

The crater rim has a much gentler slope and smooth trail so we sped up the pace a bit; I was able to maintain two steps per breath most of the way to the summit. The sun rose when we were ½ way up the crater rim. We arrived at the summit at 7am. Gaining over 3,500' in 6 hours at this altitude is a very good pace!

The temperature was -7°C (20°F) and there was a strong wind. Even with hand warmers inside my down mitts my fingertips were tingling, perhaps from Diamox, low oxygen and/or low temperature. I had packed hand warmers around the CamelBak inside my pack and had an insulated tube running outside to drink from it. In spite of taking care to blow water out of the tube back into the CamelBak every time I took a drink, I was starting to detect slush when I drank.