That's kind of a bizarre statement, since (as others have noted) the land was historically used by grazing bison, a creature so closely related to domestic catt

That's kind of a bizarre statement, since (as others have noted) the land was historically used by grazing bison, a creature so closely related to domestic cattle that they can even interbreed with them with a substantial amount of success. The same is true of similar grasslands elsewhere in the world. Lots of grazing animals, which support a smaller population of predators (including humans).