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Male bison generally travel alone or in groups of two or three. This bison grazes alone with a tiny friend perched on his back.
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Weighing about 2,000 pounds, a mature male bison relaxes on a brisk morning in Yellowstone National Park.
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Steam rises from Mammoth Hot Springs in Yellowstone National Park, Wyoming, at dawn. The water temperature is about 170 degrees F.
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At Mammoth Hot Springs, hot water rises through the soft limestone, dissolving large quantities of rock and leaving a white chalky mineral on the surface.
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Cowbirds feed on insects while riding on the back of a large bison.
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A herd of elk moves during a beautiful afternoon in May. Since elk shed their antlers during March and April, they are typically antler-free at this time of year.
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Two bison graze along Soda Butte Creek in Yellowstone National Park.
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Paloma Ponce, 5, and Alessandro Ponce, 7, play in a field of wildflowers.
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A large pronghorn relaxes in a field of dandelions in Yellowstone National Park.
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A small herd of pronghorn makes its way across Yellowstone National Park.
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Two black bear cubs rest atop the hillside. Once fully matured, black bears can reach well over 200 pounds.
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A bison’s horns can grow up to two feet in length. Here, a mother cow and her calf take a morning stroll.
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A herd of bison crosses the road at Yellowstone National Park. A herd can include up to 4,000 bison, capable of stopping traffic for some time.