El alto y La Paz Bolivia.
Is the highest.
Just to know that the flights that leave Bolivia to the US, or any other place away, they have to do a stop in Santa Cruz, since for the a/c is too hard for taking off with a lot of fuel.
So they continue the flight in Santa Cruz and there they refuel.
Nice example is AA922, it departs to La Paz from MIA
, and continues to Santa Cruz, then MIA