A lot of buffalo lived in north western New York state.

I’m sure they must have at some point in time. Whether before or after the arrival of Euros, I don’t know.

I would imagine they did until.they ran out of grassland.

Yes, definitely.

Click here and scroll down for a map.

I’ve always sort of assumed East of the river to be mostly forest

Maybe mostly. But Illinois, the prairie state, is east of the Missouri and east of the Mississippi.

Just curious: why was it important to specify “offhand”?

According to this map provided by Canadian Geographic, their range extended well east of the Mississippi.

Apparently the westernmost extension stopped at the Cascade Mountains.

@kneesox offhand implies there is nothing about the question to be considered “important”.

It is believed that buffalo, or bison, crossed over a land bridge that once connected the Asian and North American continents. Through the centuries buffalo slowly moved southward, eventually reaching as far south as Mexico and as far east as the Atlantic Coast, extending south to Florida.

Buffalo roam, and that includes forested areas. They graze on prairie grasses, but they roam woodlands too, including now. Even in the most dense forests, there is need for room to support the root base of each tree. There is plenty of tasty blossoms and grasses.
This video shows them in a forest area.

I think buffalo roam wherever they want to.

The Missouri River is not much of a boundary, and doesn’t define a different geography.

It does restrict roller skating

Yes.

And the deer and the antelope played there too.

But seriously, check out this info from a National Parks website :
https://www.nps.gov/articles/bison-bellows-9-16-16.htm

It’s an interesting & sadly familiar story, involving decimation of native people by disease and warfare, followed by comnercial overhunting by settlers.

But even today you can find bones and other evidence of buffalo herds far east of Ohio, if you know where to go & what to look for.

Buffalo, or Bos (or Bison) americanus, and bison, Bos bison, are similar, but not the same animal.

Can they interbreed? Which one has the hot wings?

You just gotta ask the hard questions, doncha?

One book I have here says they roamed the western and central plains. I can only assume the western plains are from the Mississippi River to the Rocky Mountains, and the central plains exist east of the Mississippi.
For what it’s worth…
Can they interbreed? There is beefalo, so they can breed with cattle so I can only assume they can breed amongst themselves.
The Missouri River flows southwest 2700 miles diagonally across the northern plains from Montana to St. Louis where it meets the Mississippi.

More like South-South-East once it leaves Montana. And I thought the American wilderness primarily about forests and trees East of the Missouri.

Correction on my prior post: South east, not south west. I have gotten that wrong more than once.
I flew into Atlanta once and was looking for South East Airlines. When someone asked if they could help, I said I was looking for South West Airlines. He gave me a funny look and asked if I meant South East Airlines. My bad! (I had never been back east before.)