It's hard to tell without knowing the dimensions of the track. It looks too small to be an adult wolf. Wolves have huge feet, nearly the size of your hand. It's possible that it's an immature wolf. Were there other tracks around to indicate a pack? You don't see the young ones venture off too far by themselves. Most of the single wolves I see are older age class.
I was thinking the same thing, if its a wolf, it's an immature wolf. Could be a large coyote or dog?
Hopefully that picture works... My phone hates me most days. But that picture is of a wolf track from around here and that's a quarter to help judge the size of it. Wolf tracks are much bigger than most people think.
Fred eichlar did a tv show you may be able to find on youtube. he hunted wolves hard for several days. And he gives some really cool pointers on what to look at when comparing other tracks to wolf tracks. You may be able to find his personal website and archive it there.
I don't think that is a wolf tract. I have a picture of a track beside a Dr Pepper can and the can don't cover completely, also a wolf is more open, more splayed like a Lynx. I will try to post the wolf track later.