see the link for a difference between gray and red foxes.
They mention the black on the tail for a gray fox and that a red fox will have black "booties" on their feet.
This fox has the black on the tail, although you can't quite see the tip, it does appear to be black to the tip. It also does not have "black booties", tending to say it is a gray fox. Regardless, thanks for posting.
Here is the link:
http://www.wcax.com/story/14075241/grey-fox-or-red-fox