I've seen signs on many trails in the Whites, mostly lower down (2Kish and less) around fairly flat terrain.
That being said, I saw very fresh tracks in the snow going up Israel Ridge 2 yrs ago at the end of October. Very deep snow that day (much of which was iced then melting next day, fun descent). The tracks were crossing and recrossing just up ahead of us on the trail but we never got a glimpse. Lost the tracks probably about 1,000 vertical feet below the Perch. Would that make it about 3,600 hundredish?
The other place I always see a lot of activity is Dry River Wilderness. Lots of tracks, lots of scat.
Funny story. We had hiked in to Shelter #3. Some other guys, who obviously thought they were really moutain came up a bit later. We talked, everyone had fun (except they were trying to cook on the fire ring and a Sierra Stove, late October, about 3" of snow on the ground and wet as a bog). Anyway, before we turned in, I went out to a tree overhanging the river and hung a bag. Nothing elaborate or even exceptionally sound, just enough to get it out of the shelter and just hard enough that maybe Mr./Ms. bear just gives up. The guys in the shelter thought this was hilarious! "What a wimp, no bears are coming around with 8 of us at the shelter, blah blah blah." Eat me, I'm thinking.
Next morning, there were tracks of at least 2 bears all around the shelter area (very close to the front too, the bears were definitely thinking about food in those morons' packs).
At the campground at the Loj in the ADK, my wife and I were there about 15 minutes before we saw 2 bears running like crazy through the camp w/ bear whistles and guys shouting. Next morning, I awoke to a pretty good sized bear on the back of our Subaru then climbing to the roof, spying our cooler. We were there 3 nights and each day was pretty much the same. My wife wasn't all that keen on the area!