There was a discussion last week on rockclimbing.com about htis . . . or rec.climbing, one of the two. MOst of the info said you can buy some fuel someitmes on Calle Sagarniga from teh outfitters up there. But cannisters are not only hard to find, they're not that useful at altitude . . . I recommend tracking odown the discussion, as people made specific mention of different stoves--that work on regular gas, for example--and had specific recommendations. THere's lots of propane in Bolivia, but other fuels are more difficult to get. While on Sagarniga, be sure to walk a bit further to CAlle de las Brujas to see all the peculiar stuff there.