That’s what the writer of a letter to the Pagosa Daily Post was told.
As for the number of livestock allowed on America’s public lands, the figure offered by the writer is a fairly good estimate.
The BLM sells about 12 million AUMs per year to public-lands ranchers. If you assume an average grazing season of six months per year, that’s two million cow/calf pairs.
That forage would support one million wild horses, enough to empty all of the off-range corrals and long-term pastures twenty times over.