I'm no expert, but from a quick search on google images that looks alot more like a pine marten to me than a fisher (cat). Unless of course you mean pine marten when you say fisher cat, I'm not really familiar with that term. The white belly, skinny tail and lighter brown color all make me think pine marten. Might be worth it to send that picture to your fish and game department, I know in WI they ask hunters to send in pictures they get of more rare animals, and if that is indeed a pine marten then this pic is even more special than you think. Great picture by the way!