Male elk bugling during the fall rut. Large male elk are known as bulls. Male elk have large antlers which are shed each year. Male elk engage in competitive mating behaviors during the rut, including posturing, antler wrestling and bugling, a loud series of screams which is intended to establish dominance over other males and attract females.
Species: Elk, Cervus canadensis
Location: Mammoth Hot Springs, Yellowstone National Park, Wyoming
Image ID: 19693
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 Lookout Point on the North side of the Grand Canyon of the Yellowstone. When conditions are perfect in midsummer, a midmorning rainbow briefly appears in the falls.
Location: Grand Canyon of the Yellowstone, Yellowstone National Park, Wyoming
Image ID: 13319
Grand Prismatic Spring (left) and Excelsior Geyser (right). Grand Prismatic Spring displays a stunning rainbow of colors created by species of thermophilac (heat-loving) bacteria that thrive in narrow temperature ranges. The blue water in the center is too hot to support any bacterial life, while the outer orange rings are the coolest water. Grand Prismatic Spring is the largest spring in the United States and the third-largest in the world. Midway Geyser Basin.
Location: Midway Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13571
Old Faithful geyser, sunrise. Reaching up to 185' in height and lasting up to 5 minutes, Old Faithful geyser is the most famous geyser in the world and the first geyser in Yellowstone to be named.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26939
The bisons massive head is its most characteristic feature. Its forehead bulges because of its convex-shaped frontal bone. Its shoulder hump, dwindling bowlike to the haunches, is supported by unusually long spinal vertebrae. Over powerful neck and shoulder muscles grows a great shaggy coat of curly brown fur, and over the head, like an immense hood, grows a shock of black hair. Its forequarters are higher and much heavier than its haunches. A mature bull stands about 6 1/2 feet (2 meters) at the shoulder and weighs more than 2,000 pounds (900 kilograms). The bisons horns are short and black. In the male they are thick at the base and taper abruptly to sharp points as they curve outward and upward; the females horns are more slender.
Species: American bison, Bison bison
Location: Yellowstone National Park, Wyoming
Image ID: 13120
A rainbow appears in the spray of Riverside Geyser as it erupts 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: 13367
Male elk bugling during the fall rut. Large male elk are known as bulls. Male elk have large antlers which are shed each year. Male elk engage in competitive mating behaviors during the rut, including posturing, antler wrestling and bugling, a loud series of screams which is intended to establish dominance over other males and attract females.
Species: Elk, Cervus canadensis
Location: Madison River, Yellowstone National Park, Wyoming
Image ID: 19697
Male elk bugling during the fall rut. Large male elk are known as bulls. Male elk have large antlers which are shed each year. Male elk engage in competitive mating behaviors during the rut, including posturing, antler wrestling and bugling, a loud series of screams which is intended to establish dominance over other males and attract females.
Species: Elk, Cervus canadensis
Location: Madison River, Yellowstone National Park, Wyoming
Image ID: 19700
Old Faithful geyser. Reaching up to 185' in height and lasting up to 5 minutes, Old Faithful geyser is the most famous geyser in the world and the first geyser in Yellowstone to be named.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26945
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
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
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
Grand Geyser erupts (right) with a simultaneous eruption from Vent Geyser (left). Grand Geyser is a fountain-type geyser reaching 200 feet in height and lasting up to 12 minutes. Grand Geyser is considered the tallest predictable geyser in the world, erupting about every 12 hours. It is often accompanied by burst or eruptions from Vent Geyser and Turban Geyser just to its left. Upper Geyser Basin.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13457
Grand Prismatic Spring displays a stunning rainbow of colors created by species of thermophilac (heat-loving) bacteria that thrive in narrow temperature ranges. The blue water in the center is too hot to support any bacterial life, while the outer orange rings are the coolest water. Grand Prismatic Spring is the largest spring in the United States and the third-largest in the world. Midway Geyser Basin.
Location: Midway Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13573
Grand Prismatic Spring displays brilliant colors along its edges, created by species of thermophilac (heat-loving) bacteria that thrive in narrow temperature ranges. The outer orange and red regions are the coolest water in the spring, where the overflow runs off. Midway Geyser Basin.
Location: Midway Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 13587
Yellowstone Falls from Uncle Tom's Trail. Lower Yellowstone Falls shows a beautiful rainbow as it cascades 308' in a thundering plunge into the Grand Canyon of the Yellowstone River.
Location: Grand Canyon of the Yellowstone, Yellowstone National Park, Wyoming
Image ID: 26942
Excelsior Geyser, now dormant, was formerly the worlds largest geyser. It still produces immense runoff into the Firehole River: 4,500 gallons per minute, or 6 million gallons per day. It is located in Midway Geyser Basin.
Location: Midway Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26953
Bacteria mats and Grand Prismatic Spring. The orange color is due to bacteria which thrive only on the cooler fringes of the hot spring, while the hotter center of the spring hosts blue-colored bacteria.
Location: Midway Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26954