I have seen an article arguing that bison actually over grazed themselves into extinction rather than the commonly accepted view that we shot them out of existence. You can find anything on the internet. But it all requires a suspension of disbelief.
Exactly. Not sure they grazed themselves into "extinction", but I do believe many of the early journal recordings as to being accurate as the condition of the range and the cause of that condition. Reference to the amount of cactus and lack of grass in some areas near watercourses would indicate that bison did and have overgrazed areas.If you read the old journals from trappers and the military there are references to sometimes having difficulty keeping there horses feed.