Bolivia SouthWestern Circuit Fueling Points?
 

I'm planning a trip round the southwest from Tupiza to Laguna Colorado to Uyuni and trying to figure out where I can get fuel. Looks likely I can fuel in San Pablo de Lipez and San Augustin but ideally I'd like to find somewhere near the southwestern corner too. Anyone have info? Or am I looking at either carrying a big spare cannister or organising some kind of fuel drop?

Thanks!