Gophers squirrels and porcupines

My first thought was that animal was a porcupine, but it was enormous, its bristles waved, and it looked nothing like a British porcupine! I don't think I've seen a picture of an American one. Thanks for identifying it.

There was definitely a gopher at the hot springs - the Canadians all called it a gopher. It looked just like a squirrel to me. And when I mentioned all the things that have been running across the road that are half the size of a squirrel, they said they were gophers too. I probably took a picture of a squirrel. But the map of where gophers live doesn't have them anywhere near here. Are there very small squirrels?