We've got a State Park about 60 miles north of town that has kept a herd of bison for several decades. They generally have about 100 of them, and occasionally auction off excess. They also mix in a small herd of elk with them, and they seem to get along okay.

There's also a farmer about 40 miles south who keeps a small herd, with meat for sale pretty regularly. I don't know how many he has; but have seen a herd up by the road that looked like 20 or 30, with quite a few calves.

There are, or were, two different commercial producers near Boulder CO some years ago (70s) when I was in the vicinity; but they were a far cry from free-ranging herds. More of a feedlot operation; but I believe "way back then" they were claiming around 800 head between the two places.

John