I continue year of the bear with more trees.
Can grizzly bears climb trees?
Why yes they can climb trees, according to U.S. Fish and Wildlife Service.
A common misconception is that grizzly bears, unlike black bears, cannot climb trees. While its long claws make climbing more difficult for a grizzly than for a black bear, a grizzly can get to you in a tree – it will more likely, however, be able to reach you before you reach the tree.
A grizzly bear can climb a tree with relative ease if it has branches large enough for it to grab onto, but they can't climb trees like a black bear can, especially a larger grizzly, they're much more able in trees when they're younger and smaller.
Climbing a tree is in fact an effective method of avoiding a Grizzly bear that may be following you, but it is not an effective way of escaping a bear, not unless you can climb fast and jump from tree to tree. If a bear is on the trail behind you, drop something on the trail to distract it (NOT FOOD!) leave you hiking poles, a back pack, hat, anything that might peak a bears interest or curiousity and potentially stall them on the trail while they stop to investigate. You will need the extra time to get out of the bears sight and find a tall tree to climb up and hide in.
You must select your tree wisely when trying to avoid a bear. The tree has to be tall enough that you can get up well above the bear's reach, preferably high enough that you could hide up in it, and the branches need to be small enough that the bear couldn't easily climb up after you if it were to try. You also need to be careful that the tree is strong enough that a big bear can't push it over, there have been documented cases of big bears pushing trees down to get hikers out of them.