A client on a river raft trip on the Gulkana River asked me about bear safety, and how to tell the different species of Bears that might be in the area. It's simple I told him, for safety stay in the boat. If you need to get out and go on land carry pepper spray and make lots of noise, even putting little brass bells on your clothes will help. The trick is letting the bears know you are present well ahead of your arrival. If you do find yourself in a tricky spot spray the bear in the face with the pepper spray. As far as identifying what species of Bear you might encounter look for their sign. That part of Alaska has both Black Bear (Ursus Americana) and Brown/Grizzly Bears (Ursus Arctos Horribilis). Their sign is easy to identify. Black bear tracks are generally smaller than than grizzly because the bear is smaller on average. Their claws are also closer to the paws if visible. Grizzly claws are further away from the pads of the feet. Black bears scat is usually not segmented and filled with vegetable matter like grasses and berries. Also because of their diet Grizzly Bear scat is usually segmented with hair, little brass bells and smells like pepper spray.