I agree with Katahdin! He's my favorite color of sheep He looks nice to me, but I'm really new to all this. He looks shorter in body than some of the rams I've seen, but it's hard to tell from the photos.
He's a good looking guy and I did have a katahdin ewe with a dorper ram and got a black with some brown wooly ram lamb last year...my guess would be katahdin but I am no expert at all. Only very wooly ram was our first, and he was a white dorper/katahdin cross. Our ewe Jess looked very much like your ram and was katahdin and never did shed off that wool completely. Whatever he is, he is a nice look ram for sure!