I have recently returned from a successful trip to Argentina to climb to the summit of Aconcagua. At 22,834 feet above sea level, Aconcagua is not only the highest peak in South America, it's the highest in the world outside of central Asia.

The trip required some 3 weeks of time. We flew into Mendoza, Argentina, the city nearest Aconcagua. In Mendoza we got the necessary climbing permit from the park authorities and collected last-minute supplies. From Mendoza it is a 3-hour mini-bus ride to Puente del Inca, a small tourist outpost on the highway near where the actual climb starts. The climb itself required 15 days. It could have been a few days more, but we planned into the schedule a five-day summit window so that we could wait out bad weather if necessary. As it turned out, we were able to summit on the first day of the window. We spent the spare time from our early return at a hostel in Santiago, Chile, before returning to North America.

The team consisted of 4 climbers, all of whom had prior experience at high altitude above 19,000 feet: myself, Adam Helman, John Sype, and Robert Greene. As a veteran of three prior mountaineering expeditions, one of which was an unsuccessful attempt on Aconcagua six years ago (I reached 21,900 feet), I acted as the overall leader of the expedition. Adam is fluent in Spanish and handled most logistical matters, most notably organizing support from an outfitter who provided mules to transport our supplies to base camp, and to store them at times and places not needed. John is a cardiologist by profession and acted as team physician, providing medical supplies and advice. All in all we had a very strong and diverse team with every member having unique skills to help make the expedition a success.

The climb was organized as a mountaineering expedition. What this means is that we established a series of camps along the route. To be precise, there were four camps: Confluencia at 11,000 feet, Base Camp at 14,300 feet, Lower Condors at 17,500 feet, and Camp Berlin at 19,500 feet. We had mules to transport our gear as far as Base Camp. After that, however, we were on our own. Our total inventory of food, clothing, and camping gear was so heavy (initially 350 pounds for the four of us) that we could not carry it all at once. We therefore had to carry it in multiple loads, which we left in caches at 16,500 feet and 18,400 feet. The cache at 16,500 feet was retrieved the day after setting up our camp at 17,500 feet, while the cache at 18,400 feet never needed to be carried higher; it consisted entirely of food that would enable us to wait additional time at Camp Berlin for summitable weather, which we did not need to do.

Much of the time required for the expedition was due to acclimatization, which is the process by which the body adjusts to the lack of oxygen at high altitude. If a person were transported rapidly (e.g. by a helicopter) from sea level to the summit and left there, s/he would survive a few hours. Yet the mountain can still be climbed safely because the body adjusts to this environment over a period of days or weeks. It is necessary to limit one's rate of ascent for this reason. We spent only one night at Confluencia, but then we spent five nights at Base Camp and four nights at Lower Condors before ascending to Camp Berlin to wait for a day to make a summit attempt. Adam, John, and I acclimatized well, but Robert left the expedition after two nights at Base Camp, complaining of headaches and insomnia, which were presumably due to the altitude.

On summit day I felt the altitude as never before in my life. For the last few hours before reaching the summit I took about 3 or 4 breaths per step. More notably, however, my balance was affected. My reaction to keep myself standing upright was slowed. Fortunately I was climbing with an ice axe in one hand and a hiking pole in the other, and I used these to help keep my balance. I felt dazed, as if there were a disconnect between my body and my mind. There is definitely less air atop the 22,834 feet of Aconcagua than at the 20,660 feet of Chimborazo or the 20,320 feet of McKinley. On the latter two peaks, especially McKinley, I approached the summit without breaking stride. I had no such fortune on Aconcagua. Summit weather was cloudy but not windy, and the temperature, estimated to be about 0°F to 10°F, was mild by Aconcagua standards. We had occasional views into the distance through gaps in the clouds. We stayed on the summit for nearly one hour. Adam performed a eulogy and scattered the ashes of Jack Longacre, who founded the State Highpointers Club.

Aconcagua is very likely the highest I will ever climb in my lifetime. As already mentioned, Aconcagua is the highest mountain in the world outside of central Asia. The only mountains that are higher are the Himalaya and a couple of other nearby ranges that are of a similar nature and were formed in the same manner. To climb any of these peaks is a major expense in terms of both time and money and is fraught with risk. Aconcagua represents the limit of what I'm willing to put my body through.