The road to Mendoza in Argentina runs past the resort. Try to flag down a bus or hitchhike. The hotel will organize a shuttle back to Santiago for a reasonable price.
'''Hotel Portillo''' will pick you up in Santiago and shuttle you to the mountain, it's about a two to three hour trip. Also, any bus heading to Mendoza will drop you off at the resort. However be cautious because if they shut down the road due to weather they will not let a bus through, they do let the shuttles through most of the time.
The resort is easily reached from Santiago in a few hours by car. An excellent but expensive highway (Ch$ 2200 total one-way for a small vehicle, possible to bypass a tunnel on the way back, saving Ch$ 1600) takes you to Los Andes, where you make to turnoff and start the climb to Portillo. The road from here is decent but often carry heavy traffic. Have chains with you in winter, when there is frequent heavy snow fall. The road is sometimes blocked by trucks failing to do the ascent to the border.
Getting a lift on a truck is an easy prospect, as there are a constant trickle of them ''slowly'' making their way to and from Argentina. But the smaller car the faster. You'll save hours (or even ''days''!) if picked up by private vehicle.
If put off by the steeply priced ski passes, you can ride the lower slopes and hitchhike back up with trucks. Bring your own gear or rent in Santiago and try to look as if you actually ''do'' have a pass. Although very possible for adventurous travelers, it's not generally recommended. Critics of this money saving activity argue that the tickets are less expensive than in the US and on par with Europe. They also call skiing without a ticket "stealing", a description budget travelers find preposterous and wrong in every important way. What ever is your belief, you will not get to take full advantage of the higher mountain terrain without utilizing the lifts. And consequently will be rather bored - if you're not a decent skier don't come here and if you are you ''need'' a lift pass and ''want'' the helicopter.
Make sure you get to Tio Bob's. Lunch on the top of the mountain offering spectacular views of the resort.
Cigarettes before you get here, if they close the road due to snow you may find smokes get rationed, having a supply of your own will (1) keep you sane if you are fond of the evil weed and (2) make you extremely popular in the bar and club.
Don't leave Portillo with out having quite a few ''Pisco Sours''. It's a Chilean speciality and the mascot of the mountain. It's made from grapes along the lines of Brandy. There is a bar in the hotel.
'''The Posada''' is the spot where all the locals hang out. It's right outside the hotel and 1/2 the price. Gets busy after midnight when the workers get off for the night.
'''Hotel Portillo''' is the only hotel in the resort. You can stay at the deluxe Hotel or the hostel.
There is no organized camping close to the slopes. When going backcountry you'll find most flat spaces along the noisy road. Toilets are available in the hotel for non-guests. Bring warm sleeping gear in winter.
If you've got the wonga and the weather's right for it, take the helicopter transfer. Just don't touch the quick release door lever....