My eyes aren't the greatest any more but I saw what looked like a horseshoe print also. I also noticed it was pretty defined and on top.

The part that looks like it might be Hogs, is at the top of the cleared area. Many times Hogs try to kind of roll the grass up and over, roots on top, grass blades on the bottom. But then again sometimes they go deeper (or try) to get to roots or bulbs.

Then again maybe it is just someplace a larger critter took a dust bath, maybe some old Rodent burrows or a Mole hill.

A couple of tips, Google earth is your friend. There really aren't any rules, I've spooked pigs and even shot one within yards of where I parked my truck to go hunting. But find paces on Google earth or a map that have cover, water and find places that are likely to have food. Take a ten mile drive in kind of a box pattern around your hunting area if possible, way early A.M. and look for places the Hogs may have crossed the road. Real easy to see where they've crossed after a rain, looks like the muddy path the kids leave in the kitchen.

You may be able to tell which places are likely to be the bedroom and which likely to be food and water. Setting up between the two isn't a bad idea. Putting up something that throws out a good sent cone my also prove fruitful, you may be off the normal path. But if they smell something interesting they may come in to investigate on their way by. If they find something yummy they may visit that spot again.

The down side to drawing the Hogs in is they can and often do spook the Deer, especially the ones ready to drop or with new fawns. They eat fawns. Many times I've known the pigs were coming way before they got near, because the Deer took off in a panic. But like I've said, there really aren't any iron clad rules, just tendencies. I watched a giant Sow feeding maybe twenty feet away from a Doe and Fawn, that was a real head scratcher.

Have you noticed any armadillos? They can mess a area up.

I second chief joe's guess. Hogs will usually leave clumps of overturned sod. The first thing I thought was armadillos.

Fresh Hog sign