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Update: last updated on 11/10/2015.

Cerro San Lorenzo. 3706m.


Cerro San Lorenzo is a 3706-meter peak located in the border between Chile and Argentina in the vicinity of the 48th parallel, just north of the Perito Moreno National Park.

The most interesting climbing on this peak is on the east and northeast face. This is where the “future” lies. The northwest and west side of the mountain, accessed from Chile are not as interesting from a pure climbing perspective.

This write up focuses only on the east and north east side of the mountain, as an attempt to inspire folks to visit the area. For information on the normal route of Cerro San Lorenzo, climbing history of the peak or surrounding area, further information on the climbs mentioned here, etc, see the “Where to find much more information” section lower in this text.

If you decide to visit the east side of San Lorenzo note that to the east and north there are a number of other peaks, Cerro Hermoso, Cerro Dos Picos, Cerro Penitentes, so even if you don’t climb San Lorenzo you can easily do a number of other climbs and have a great trip.

How to get to the east and northeast face.

The east and northeast face can be accessed from the north, from Lago Posadas via the Rio Oro or from the south via the Perito Moreno National park.

Since for a number of years there have been issues with one of the land owners along the Rio Oro, who has demanded up to 1200 dollars per person to pass by his property, the approach from the south via the Perito Moreno National Park is the preferred route.

Unless you have your own car to get to the Perito Moreno National Park you will need to fly to Rio Gallegos, then take a bus to Gobernador Gregores (once a day via Taqsa, cost in late 2013: 230 pesos one way -call the bus terminal of Rio Gallegos to confirm: + 54 2966 442159) and there you will have to hire a car or truck to take you in the remaining 200 kilometers to the Park. Ask Virginia and Abel at hotel Cañadon Leon, located in Roca street 397, phone + 54 2962 491082 (Spanish only). They have provided transport to many climbers in the past. The approximate cost for drop-off and pick-up is U$800 (over 800km of driving in all). Make sure you also discuss a pick-up date for the return trip and either arrange a specific date or discuss calling her via radio (from the Park’s office) or satellite phone (if you carry one) to coordinate.

There are two estancias in the area that work work with tourists, Estancia Menelik and Estancia La Oriental, but services at both are expensive. Although you will only walk a few kilometers inside the national park (the peak is in a provincial reserve) be sure to get a permit and tell them what you are doing. I would suggest contacting the park ahead of time to let them know you are coming. You can find basic info about the park as well as contact info here.

Ask your ride or drive past Puesto Rincón, to the end of the road. From here you will continue on foot, hiking three hours to reach Puesto San Lorenzo, which is a good place to establish a basecamp. The land north of the national park including Puesto San Lorenzo used to be private but it was donated by its owners, Doug and Kris Tompkins to the National Park.

You will have to carry all your loads to basecamp on your own back because pack-horses are not permited within the park. If you plan on leaving your supplies at the end of the road, ferrying them to Puesto San Lorenzo slowly and as needed, take plastic barrells or similar, something that can be locked and where food can be safe from rodents. Alternatively, you can leave your supplies at Puesto Rincón, but this will mean that each time you will walk an extra 45'.

Note than it is not possible to approach the south side of the peak from the south (it would be far shorter). The area to the south of the peak is rated as "zona intangible" by the National Parks Administration, meaning that for conservation reasons it is closed to humans. To access Pilar Sur you have to head north to Puesto San Lorenzo, then west onto the glacier, then back south. No point in asking or complaining about this, these are the rules.


There is a big supermarket in Gobernador Gregores where you will find everything you need. You can also find white gas (solvente) in Gregores. Bring all specialty mountains food: bars, gels, freeze dries from home and buy propane canisters and other unusual items in Rio Gallegos.

What to bring.

Because the area is fairly remote a satellite phone could be a useful tool. If you have one then you can ask a friend or family member to send you regular weather reports. For instructions of how to send a satellite text message with all relevant weather forecasting info see here.

Note that if you plan to climb a route in the east face and descend to the west, to Chile, you will need your passport and some cash (in case), plus a good map and a GPS to find the descent down the De Agostini route in a storm.

When to visit.

For any of the climbs in this face you need cold weather, as cold as possible, so the earlier the better. Consider going between October and December. Note that in September the road can at times be impassable (mud, snow, water). January and February are usually too warm. Mid-March and later might also provide good conditions.


There is no rescue team anywhere close. If you have an accident you are on your own. Your only option is self-rescue. There are no helicopters available either. Take a well furbished first aid kit and climb with a big enough team (at least three people - preferably more) to have the man-power to carry out self-rescue. Every member of them team should be capable. This is no place for siesta or a picnic. If you get hurt, you are fucked. Even body recoveries are virtually impossible in that area. Make sure you plan ahead of time for a potential emergency - read the risk managment doc we put together: here (in spanish here). Also read the fine print in your rescue insurance policy carefully, so you know what is covered and what is not. Any intervention will cost upwards of U$20,000, so make sure your policy covers that amount or more.

Climbing routes from the east, NE and north.

The purpose of this write up is not to showcase what has been done, but to showcase all the virgin terrain that remains, including an impressive tower to the far south of the east face, the Pilar Sur, reknowned for bad quality rock (very fractured granite). Regarding the east face one important note, the face is crowned in many places by what looks like a serac or large cornice. It is unclear if these cornices or seracs are active or not. They appear not to be but that is a judgment call that you will have to make. In late 2009 English Mick Fowler and Es Tresidder visited the area. After the visit Es wrote me an email saying the following: “The main problem though was that we failed to find an objectively safe-enough route on the whole east face, despite lots of looking!  Looking back we reckon there is only one line in the whole 4km long wall that is not either threatened by very active seracs, or terminates in a 100m+ high, overhanging cornice! That line would be very hard, too hard for us we decided, but it does look very good, like a harder version of the Moonflower buttress!”

1. East ridge. Sudafricana. A 1500-meter long classic mountaineering route climbed by South Africans Hans Petter Bokker, Russel Dodding, Paul Fatti and Erwin Muller in 1986. It has been repeated a number of times, including one 10-hour ascent by German climbers Hans Holzmayer and Sebastian Thaller in 1995.

2. NE Face. Nordafricana. Climbed by Catalans Oriol Baro and Jordi Corminas in 2008, in 30 hours round trip. They climbed to the base of the summit mushroom where they joined the Sudafricana and from where they retreated. This is the first line to tackle the NE face, one of the steeper and more interesting faces that San Lorenzo’s offers. French Jean Annequin and Simon Destombes had made an attempt in 1998, climbing 1000 meters before retreating.

3. North face. American. Climbed by Americans John Hauf, Timothy Rawson and Tom Walter in 1987, to the base of the summit pyramid from where they retreated (see AAJ 1988 pp. 173-174). In late 2014 JP Auclair and Andreas Fransson died in this couloir when they were swept away by an avalanche. They were climbing up with skis on their backs, in hopes of skiing it. The avalanche started above, the result fo warm temperatures. If you plan on climbing this line, only do so when it is cold, and even then go very very early in the day.

4. North face. Cafe Cortado. Climbed by Italians Herve Barmasse, Matteo Bernasconi, Giovanni Ongaro and Swiss Lorenzo Lanfranchi in 2006. Follows the American line for the first 1000 meters and where the Americans climbed up and right continues straight. In that section lies the crux of the climb: a short but difficult S-shaped goullote that brought them to the summit mushroom. They reached the top in ten hours of climbing.

In the east face of the ridge that heads north from the North summit, above the Río Oro glacier (best approached via Río Oro), there is at least one climb, completed by Argentines Ramiro Calvo and Nicolas de la Cruz in the early 2000s. This face is shorter than the east face of the Main, Central and South summits, but it is steep and likely could be home to a number of interesting climbs.

5. Pilar Sur. Pilar Sur is the big tower at the south end of the east face. It's north face has over 1000m of vertical gain (likely around 1200m). The rock is far from good. Note the amount of rockfall debris at the base after warm periods. In 2013 Luciano Fiorenza, Pablo Pontoriero and others made an attempt, climbing eight pitches and retreating once they realize that the rock did not improve higher up as expected. You can read more about their attempt here.

6. Aguja Antipasto. In November of 2014, Colin Haley and Rob Smith climbed the small tower to the east of the Pilar Sur, which they christened Aguja Antipasto, as a reference to being merely an appetizer in comparison to the main course just behind. They climbed 14 pitches with difficulties to M5R 6a+ and a few moves of A0. They descended the route in 12 rappels. They named their route “Romance Explosion”. The ascent required 22 hours round-trip from a bivy in the glacier below. The poor rock quality requires slow climbing. More info here.

Where to find much more information.

There is an excellent little guidebook to the San Lorenzo area written by Silvia Metzeltin Buscaini. It is in Spanish and can be purchased here.

Also you might want to buy a copy of Silvia Metzeltin and Gino Buscaini's book: Patagonia: Terra Magica per Alpinisti e Viaggiatori (Dall'Oglio, Milano, 1987). The Italian version can be purchased through Amazon. It is an excellent book, well worth every penny. The Spanish version published by Ediciones Desnivel is of much lesser quality than the original and has many translation mistakes.

The ninth issue of the Cuadernos Patagonicos, published by Tecpetrol (Techint) was dedicated to Cerro San Lorenzo. A Spanish online version of that can be found here. It is somewhat outdated, but it is still a good source of information.

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Photos (click to enlarge)

San Lorenzo - Río Lacteo approach

San Lorenzo - east face

San Lorenzo - east face

San Lorenzo - east face

San Lorenzo - east north east face

San Lorenzo - north face


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