El Portillo is very accessible thanks to the closeness of the road up to Portozuelo Argentino (pass) and can serve as a good acclimatization summit for example Tupungato.
The views from the summit is excellent. To north or south you see Los Andes go on and on to the horizon. To the west, the highest peaks of the area are clearly visible and to the east the lowlands of Argentina spreads out 4000m below.
The peak could be a horrible task to climb. I was there in the penitentes season. In 2006 that was in January and I guess that's the normal time. It's extremely taxing to negotiate penitentes, especially if they reach a height of a meter or two. When I was there there were penitentes all the way up to the summit!
I have not been in the area in season for "normal" snow, but I can imagine a combined ski and mountaineering trip to the area can be very nice and the climb of El Portillo and easy ascent on up to 50 degr. slopes.
When there's no snow in any form, either walk on the scree and rocks or scramble and climb on the ridges.
Beware of very rotten rock!
This applies to the whole area.
A more detailed description on how to get to the area on the main page.
Argentina - Mendoza - Tunuyán - El Manzano.
The above part of the approach can at all times be done with a motorized vehicle.
From Manzano; pay for a ride with a 4x4 and go as long as the road conditions permit. Snow, flooded rivers and land slides may make it impossible to all the way to Portozuelo Argentino. If so, walk along in the main vally until you see El Portillo's long ridge blocking the way. If there are switchbacks visible or if the road is clear just follow them. If not, take aim at the lowest point of the ridge. This is where the pass is located.
Go up to the pass and down on the other side. Head to your left and find a camp spot. Penitentes fields may make this very difficult and if they are too high, camp on the pass. If you camp here, you have about a 100m to down and then 600 vertical meters to the top of El Portillo's summit.
Alternative routes could be to go straight from the pass along the ridge, but count on very rotten rock and a dangerous traverse on the rugged ridge.
The mixed terrain of the higher parts
The route itself doesn't hold too much difficulties. It's just a matter of finding the path of least resistence towards the summit.
Some things I find useful to mention.
At some points when scrambling up, it's not obvious which is the highest summit, but hold to your left at all times in the main couloir at all times. More to the right, there are some steeper sections where you're bound to either end up on very loose and steep scree or on small rocky ridges where the rock crumbles when you touch it.
If you follow the path of least resistence you probably end up on the summit ridge some rocky bumps to the left of the highest point. Climb over these or traverse below them until you are at the summit. Some old pieces of cloth marks the place.
Sturdy hiking boots.
Gaiters is a must or you'll loose your mind from all the gravel in your boots.
Good sun block and sun glasses.
External LinksUseful info on this page about biking in the area.