Bison surrounded our minivan. Big ones and little ones. Some weighing about a ton, strolling 3 feet outside my window. This was so Yellowstone.
Park rangers do their best to educate the public to stay well away from wildlife: 100 yards from bears and wolves, 25 yards from everything else.
In busy parts of the park, such as where an elk herd likes to chew the green grass in front of Mammoth Hot Springs Hotel, frustrated rangers yell "Keep back! You're too close!" as a grandma from Ohio or Iowa waves her camera phone at a burly bull elk that could gore her in a selfie-taking second.