Bull elk, antlers bearing velvet, Gibbon Meadow. Elk are the most abundant large mammal found in Yellowstone National Park. More than 30,000 elk from 8 different herds summer in Yellowstone and approximately 15,000 to 22,000 winter in the park. Bulls grow antlers annually from the time they are nearly one year old. When mature, a bulls rack may have 6 to 8 points or tines on each side and weigh more than 30 pounds. The antlers are shed in March or April and begin regrowing in May, when the bony growth is nourished by blood vessels and covered by furry-looking velvet.
Species: Elk, Cervus canadensis
Location: Gibbon Meadows, Yellowstone National Park, Wyoming
Image ID: 13154
A rainbow appears in the mist of the Lower Falls of the Yellowstone River. At 308 feet, the Lower Falls of the Yellowstone River is the tallest fall in the park. This view is from the famous and popular Artist Point on the south side of the Grand Canyon of the Yellowstone. When conditions are perfect in midsummer, a morning rainbow briefly appears in the falls.
Location: Grand Canyon of the Yellowstone, Yellowstone National Park, Wyoming
Image ID: 13329
Morning Glory Pool has long been considered a must-see site in Yellowstone. At one time a road brought visitors to its brink. Over the years they threw coins, bottles and trash in the pool, reducing its flow and causing the red and orange bacteria to creep in from its edge, replacing the blue bacteria that thrive in the hotter water at the center of the pool. The pool is now accessed only by a foot path. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13352
Crested Pool is a blue, superheated pool. Unfortunately, it has claimed a life. It reaches a overflowing boiling state every few minutes, then subsides a bit before building to a boil and overflow again. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13355
Riverside Geyser at peak eruption, arcing over the Firehole River. Riverside is a very predictable geyser. Its eruptions last 30 minutes, reach heights of 75 feet and are usually spaced about 6 hours apart. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13366
A visitor videotapes the eruption of Lion Geyser, with Old Faithful Inn visible in the distance. Lion Geyser, whose eruption is preceded by a release of steam that sounds like a lion roaring, erupts just once or a few times each day, reaching heights of up to 90 feet. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13371
Daisy Geyser erupting with visitors visible in the distance.. Daisy Geyser, a cone-type geyser that shoots out of the ground diagonally, is predictable with intervals ranging from 120 to over 200 minutes. It reaches heights of 75 feet, lasts 3 to 4 minutes and rarely erupts in concert with nearby Splendid Geyser. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13382
Sawmill Geyser erupting. Sawmill Geyser is a fountain-type geyser and, in some circumstances, can be erupting about one-third of the time up to heights of 35 feet. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13385
Castle Geyser erupts, reaching 60 to 90 feet in height and lasting 20 minutes. While Castle Geyser has a 12 foot sinter cone that took 5,000 to 15,000 years to form, it is in fact situated atop geyserite terraces that themselves may have taken 200,000 years to form, making it likely the oldest active geyser in the park. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13417
Castle Geyser erupts with the colorful bacteria mats of Tortoise Shell Spring in the foreground. Castle Geyser reaches 60 to 90 feet in height and lasts 20 minutes. While Castle Geyser has a 12 foot sinter cone that took 5,000 to 15,000 years to form, it is in fact situated atop geyserite terraces that themselves may have taken 200,000 years to form, making it likely the oldest active geyser in the park. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13426