I always have bear spray on my bino harness up in the park...sometimes I do bail out of the car without my bino harness though. I don't carry firearm in the park but we are really just "road hunting" and cautious about maintaining distance - my wife loves the park but refuses to venture much beyond sight of a good sprint to the car!! Outside the park, in the GYE periphery, fishing, hiking, hunting, etc - I carry bear spray and firearm on bino harness all the time...I may forego the gun if we are in a pretty occupied campground or the like.
I did get myself, with an assist from the Mrs., into a much closer than desired griz bear encounter last year. We came across a small gathering of cars and folks set up with optics/cameras/etc on roadside. I bailed out sans bino harness/spray and moved up the road where a sow with two cubs were feeding up the hill, not much over 100yds away. My lovely wife remained in safety of the car. Pretty quickly the sow and cubs fed up out of sight onto the bench above. The crowd that was on foot all started hustling up the road - I was just shooting with a 300mm off a monopod so did quick pack up and started striding down the hill back to our car. I'm still not sure how they collectively all pulled this off but every remaining car, including my wife in our car, fired up and drove off up the hill as well. Very quickly I was completely alone not much over 100yds from sow with two cubs, out of sight just above me. I turned and started hustling up the hill to catch up to the herd and glanced up to see this - momma changed her mind apparently and was coming back down:
Sheee-it!! I'd guess 85yds max. I took quick inventory of my resources - there were none so I started backing back down the hill just as a solo guy in a Subaru came idling past then stopped when I waved at him. I quickly knocked on his passenger window, he popped the door and I told him there was a sow with two cubs right above us and could I jump in if they come closer. He gave me the thumbs up, pulled to the roadside and I took shelter behind his car and we got some great shots.
Suspiciously, that was not the first time my wife has sped past me with a nefarious look on her face to drive down the road to put a grizzly between me and the car...seems sus to me anyway...

She stranded me with this sow and cub between us once but I had myself mixed up in a crowd of folks I'd sized up as slower, more tender, and better eating than me!
Anyone know if there is an optimal ratio of bear spray canisters : bear(s)...I have wondered if at times a fellar might just find himself out gunned: