There was one day of grizzly photography that was so spectacular I simply refer to it as The Day. It happened like this: Each spring as the bison migrate back onto Yellowstone's northern range, they have to pass Blacktail Ponds. These ponds span the valley, and as the bison cross the rotting ice a few fall in and drown. The grizzlies emerging from hibernation, mostly boars, know this and make a beeline for the ponds. Early on The Day, there were four bears in the area. Two left before light, and two stuck around as it got light. The dominant bear controlled the carcass while the other had to wait his turn. You could almost hear him thinking: "As long as I have to wait, what can I do to make these photographers happy? I'll bet they'd like it if I went over to this snowbank and rolled around and played with my feet. Then I'll bet they'd like it if I went for a swim in the pond, breaking the ice and splashing in the water. Then, if I laid down right in front of them and chewed on some old bones, they'd really like that." For about half the day it was like this bear was following a script. When coupled with images of the other bear on the carcass, and coyotes trying to steal meat, The Day was pretty exceptional. See all the images in the Grizzly Bear gallery.