Bear Sign?

Lately, there have been several sightings of a black bear around here, though none to my knowledge in our particular neck of the woods.  However, I recently noticed that several large boulders were overturned in an area I regularly walk.  One has what could be bear claw scratch marks - hardly proof positive of ursine presence, I admit.  But then there's also potential evidence at the pond just a little further through the woods.  I saw that the plant growth at the edge of the water has been raked ashore in several places, and took a photo of long scrape marks left on the pond floor at one of those sites.  Lots of crushed grass in places, too.  Could this be the result of a bear pulling in and sifting through the plants to glean the various frogs, crayfish and other small critters that hide there?  It wouldn't surprise me, since my dogs routinely do something similar.  And bears are known to forage for food up to 20 hours a day at this time of year.  It's conceivable that these are legitimate signs of the bear so many have seen.  I'm keeping my eyes open, though, for that clawed-up tree, big pile of scat, or perfect pawprint that will make a true believer out of me.