The necessity of vast herds of large ungulates have long been recognized as a critical part of the North American ecosystem. Either bison or cattle will demonstrably work. Regions that have largely been abandoned by cattle ranchers, whether due to economics, environmental destruction, or regulation, have been ecologically devastated in the absence of wild bison to fill the ecosystem gap. Bootstrapping new herds of bison in these areas will transform them in a positive way. In the Mountain West, the introduction of free range cattle in areas that were previously off-limits has had a similar effect.

This is related to why eliminating beef agriculture in large parts of North America would have limited impact on ungulate methane emissions. Without replacing them with vast herds of bison, which similarly emit methane, the ecosystems die.