The Barcroft Laboratory is the 2nd highest of the facilities available at the White Mountain Research Station, at about 12,470 feet up in the White Mountains, on the flank of Mt. Barcroft. The only higher facility is the White Mountain summit facility. In the picture I have hiked up to the 13,000 foot level, behind the laboratory. It was cold & windy, but fairly dry, and climbing 600 feet at that altitude is a chore for me. The picture was taken by Gordon Hoover, and shows the peak of White Mountain in the background, directly over my head.
The Reagan Solar Radiometer (pictured here) needs to be calibrated in an atmosphere as free of water as possible, and that means as high as we can go. The Summit Station is unmanned, only a few thousand feet higher, and difficult to get to by comparison. So we just stayed at Barcroft, which has dormitory facilities and an onsite cook.
I set up the radiometer to start tracking the sun at dawn, and track through midday. The air in the morning is still relatively calm and gives better data than the afternoon air, which has had time to build convection cells and thermal gradients, making it less suitable for our purposes. We tried on both October 7 & 8, but there were too many clouds later in the morning of the 7th, whereas the 8th sported excellent clear skies until nearly noon, when the clouds no longer much mattered. So on the afternoon of the 8th we hiked uphill a bit, to a plateau area where this picture was taken. The walk was probably no more than a half mile or so, but uphill at 13,000 feet, so you have to stop and breathe occasionally.
Sleeping (or more accurately not sleeping) was the biggest problem at that altitude. The caretaker/cook had no problems, but he was quite used to it. But for newcomers it just doesn't work. Once you start to nod off and your respiration rate drops, you don't get any air and you wake up suddenly gasping for breath. It goes on like that all night, and two days just isn't enough time to really get aclimated.
Other than the sleeping, the altitude did not cause me any major discomfort, which was my experience for my one night on Mauna Kea as well, back in 1987. However, there are oxygen bottles and breathing masks placed conspicuously around all of the high altitude facilities, and one of the first things you do upon arrival is to learn how to use them, just in case.
The afternoon of the 7th was also free time, and we visited the the Crooked Creek Laboratory, as well as the Patriarch Grove of bristlecone pines, the oldest living trees on the continent.