Spring is a good time to view the animals of Yellowstone National Park. We went in the west entrance the 2nd day the park was open to car traffic, (April 21). Photos were taken with a simple HP digital camera, no extra lens. We saw bison, elk, 2 grizzly bears, a coyote, bald eagles, osprey, and many ducks, geese, swans, and ravens. Most animal photos where taken from the car, I respect those big mammals. http://www.nps.gov/yell/