We spent a month driving and camping in Alaska in 1999. The only bears we saw were in Denali. We saw lot's of moose, humpback whales and eagles but very few bears.
It's common to see bears near salmon streams in June through early September, or at the bear observation points mentioned here. By August or so they can be found eating berries on higher elevations, or in any other areas that contain berries. I have seen quite a lot of bears by Summit Lake, right off the road, gorging on salmon.




