The more the better, but there's already a "European Yellowstone" in the form of Belovezhskaya Pushcha National Park in Belarus, of similar size, home to many of the remaining European buffalo.
I'm guessing you mean the bison. (At least that's what Belovezhskaya Pushcha is known for, other than being the largest area of primeval forest in Europe.)
I know in Polish, "żubr", which is the European Bison, is often translated as buffalo and the American Bison is known as "bizon" which is understandably translated as bison. I would not be surprised if Belarusian was similar.