I've from a bit north of the OP, right in the middle of the state. I'd have to say that I really can't believe that is bear dung. First, bears aren't really moving about too much right now. They're denned up waiting for spring (for the most part). Second, that would be an enormous pile for the black bears here in PA (thew hole pile would be closer to the size of the $ bill usually). Third, it appears to be composed mostly of graze items like grass or hay. This time of year, there really isn't much of that kind of browse around. That's why the deer and other grazers are eating bark and digging up roots this time of year. If a bear were active, I would think it much more likely that it would be feeding on higher protein foods like road kill and winter-kill carcasses. With fall/winter hunting seasons in full swing, there would be fairly plentiful gut piles and other "unclaimed" carcasses about as well. Those would be much more beneficial to a bear at this time of year. I think a large ruminant on frozen ground is a bit more plausible IMHO.
Bigger than a quarter horse...that's funny. I wonder if you could break even on a $ horse though.