>>2778759Died of disease and war, dumbass. Starvation only became an issue after the buffalo were very nearly hunted to extinction, during which times natives were not allowed to hunt across their traditional ranges anyway, but were restricted to much, much tinier areas.
Even when Lewis and Clark went on their expedition, they went though villages that were completely empty, utterly eradicated by disease carried by French trappers that did most of the initial exploration.