Where you are going they have no fear of humans, or little practical concerns. Walk away. Don't meet their eyes. Don't run. Walk not directly away but at angles. If attacked, fight back. Authorities will tell you to lie down and play dead. I would not do that. There is a growing 'movement' among knowledgable persons that lying down and playing dead is a good precursor to being dead. Climb a tree. Grizzlies generally can't climb well. But smaller ones will have more success scraping their way up the trunk. Talk to the Rangers about where the Bears will be this time of year. There are known haunts.
Personally, I would carry as little food on me as possible. REad NOne, maybe a single meal just to get me in to where I wanted to go. If allowed, I would take a khukuri. It would beat swatting the thing with a forest service permission slip. They might allow pepper spray. Pepper spray has mixed reviews, evidence being it seasons the bearer for the determined bear who likes sechuan chinese food.
Try to keep a layer of tourists between yourself and the bear.
People who've had incidents with the great bears swear they will never hike or play in any place they cannot be legally armed. I listen to this, and make my own excursions into the "Parks' minimal. There are many majestic and wild places without such restrictions.
This topic makes me disgusted with my fellow americans. This America is becoming more theirs than of mine and those who share my ideals.
all this aside, you'll have a great time and probably no problems.
oh, one more thing; this time of year they may have exhausted the food supply higher up and be traveling to rivers and lower lands in search of berries and other foods. If this is the case, head for higher up.
munk