I am incredibly upset with some of the 'wildlife photographers' in town right now.
These animals deserve our respect!! Realize that it is elk mating season, a very important time of year for the entire population, and give them space. Realize that the bear grazing on the side of the road only has a few weeks before hibernation, and these could be his last few calories that you are chasing him away from. Realize that the mother moose and her calf are trying to gain weight and strength, and every time you force them to leave their food, you are potentially hurting their chances of winter survival.
This may seem like an exaggeration, but it's not. Please be smart, dont forget you're in a National Park and know when it's time to leave.