Yellowstone: Mammoth Hot Springs

This is the concluding post for our June vacation to Grand Teton and Yellowstone National Parks and Yellowstone geologic features.

On the second-from-the-last day of our week in Yellowstone, we took a day off from wildlife to see geologic features. At the end of the day, just after seeing the bear cub eating in the meadow, we stopped at Mammoth Hot Springs.

Here’s the hill of travertine at Mammoth Hot Springs. Unlike other Yellowstone hot springs that are rich in silica, Mammoth Hot Springs is a hot spring in a limestone area. Limestone, rich in calcium, is formed in oceans by coral. As hot water is pushed through limestone, the calcium dissolves and is carried to the surface, where the water evaporates and leaves the calcium behind. Limestone deposited from a hot spring is called travertine.

hill of travertine at Mammoth Hot Springs
hill of travertine at Mammoth Hot Springs (click to expand)

Most of the hill is white, but the terraces on the left are a more-interesting, rusty color. They’re called Minerva Terraces.

Minerva Terraces
Minerva Terraces (click to expand)

The photo below, taken at a wider angle, shows the wide variety of colors in the surrounding terraces. As with the other hot springs, the color comes from microbes or impurities.

Minerva Terraces
Minerva Terraces (click to expand)

Travertine is used as a building material; the Roman Colosseum is made of travertine. Limestone, rich in calcium, is a key ingredient in Portland cement; there is a cement plant in Cupertino, California, near our home.


Yellowstone: Hot Springs and Geysers

This post is part of a series on geologic features we saw in Yellowstone National Park during our June vacation in Grand Teton and Yellowstone National Parks.

As we got closer to Old Faithful, we saw steam rising in the distance. Shown above, the Lower Geyser Basin has hot springs and geysers.

Carbon dioxide bubbles to the surface of this hot water pool. The pool appears to have blue water, but the park service provides this explanation. When sunlight shines into the clear, deep water of the pool, the blue light is scattered the most, causing the water to appear to be blue. The shore around the pool isn’t blue, indicating there’s nothing blue in the water.

carbon dioxide bubbles
carbon dioxide bubbles and steam from a blue pool of hot water

Viewed from above, this pool is blue where it’s deepest. Something white accumulating is accumulating  along the edges of the pool.

blue pool seen from above
blue pool seen from above

Seen below, heat-loving microorganisms consume some of the gases and help convert them to sulphuric acid. The acid breaks down the rock to form clay — clay that mixes with water in mudpots.

The Midway Geyser Basin has larger pools. See the people in the background.

large blue pool of hot water
large blue pool of hot water

Water-filled terraces formed by minerals in the water make an abstract image. The rising steam obscures the wooded hill in the background.

abstract -- terraces
terraces (click to expand)

Random terraces shot from a low angle form an abstract image.


The Grand Prismatic Spring is a hot spring 200 feet wide with varying colors shown in the rising steam. The blue steam is from the deep water in the center of the pool. Cooler water around the edge of the pool supports organisms with yellow, orange and brown colors.

aerial view of Grand Prismatic Spring (google map)
aerial view of Grand Prismatic Spring (google map)
colored steam from Grand Prismatic Spring
colored steam from Grand Prismatic Spring (click to expand)

Finally, this hot spring at the Black Sand Basin shows vivid colors around the edge.

hot spring at Black Sand Basin
hot spring at Black Sand Basin (click to expand)

Yellowstone: Grand Canyon of the Yellowstone

This post is part of a series on geologic features we saw in Yellowstone National Park during our June vacation in Grand Teton and Yellowstone National Parks.

We started with the south rim of the Grand Canyon of the Yellowstone. The upper falls of the Yellowstone River, shown here, is 109 feet high. The photo below is underexposed to show the waterfall. To get a sense of perspective, see the people standing on the lookout point just to the right of the waterfall.

upper falls, Yellowstone River
upper falls, Yellowstone River

The lower falls is much higher, at 308 feet high.

Lower Falls
Lower Falls

This wide-angle photo from the same spot shows the yellow stone of the Grand Canyon of the Yellowstone. The rock is rhyolite, which is high in silica, an ingredient of sand. The Canyon was formed by erosion.

Grand Canyon of Yellowstone
Grand Canyon of the Yellowstone

We drove to the north rim to see this rocky spire with an osprey nest at the top. Trout washed over the falls might be easy pickings for the opsrey.

osprey next on rocky spire
osprey nest on rocky spire

Yellowstone: Old Faithful

This is the first of a series of posts about geologic features we saw in Yellowstone National Park during our June vacation in Grand Teton and Yellowstone National Parks.

Toward the end of our week in Yellowstone, we returned to the Old Faithful area to see geysers and other features related to hot water. Yellowstone was formed due to volcanos and has the most geysers in the world, more than Iceland or New Zealand.

This diagram shows the cycle of water in these hydrothermal features. The blue arrows down the sides of the diagram show surface water from rain or snow being absorbed into the ground. This ground water is heated by the magma close to the earth’s surface. The heated water, shown as red and blue arrows, tries to expand and migrates to cavities or or porous rock, creating pools of boiling water. The pressurized water finds a channel to the earth’s surface. If the channel is narrow, water will occasionally spurt out, forming a geyser.

Yellowstone's hydrothermal features
Yellowstone’s hydrothermal features

In the geyser photo above, note the white mound around the geyser. It’s a feature of a cone geyser, which forms a cone around the geyser opening. Cone geysers function like a nozzle spouting water. Deep in the earth, heated water dissolves and transport silica, the same mineral found in sand and glass, to the surface. During geyser eruptions, silica is deposited around narrow vents or opening. Over time, this mineral, called geyserite or sinter, forms mounds of varying sizes and shapes.

Old Faithful is named because it erupts faithfully, on a uniform period between eruptions. When we arrived at Old Faithful, we looked at the prediction for the next eruption and found we had some time. We walked to the nearby Old Faithful Inn, the largest log structure in the world, and marveled at the stone fireplace and logs. We don’t see stone fireplaces this tall in California, earthquake country. With the volcanism in Yellowstone, they do have earthquakes. Perhaps the fireplace has been rebuilt to seismic standards in the 100+ years since it was built.

Old Faithful Inn lobby
Old Faithful Inn lobby

Watching the time, we found a place near Old Faithful in time to enjoy the geyser erupt. Here’s our video.

Yellowstone: Bears

This is part of a series of posts about wildlife we saw in Yellowstone National Park during our June vacation in Grand Teton and Yellowstone National Parks.

Yellowstone has two kinds of bears: grizzly bears and black bears. Grizzlies are brown bears, larger than black bears. Grizzly bears have longer claws and can’t climb trees like black bears can. Both can run faster than humans.

We had three notable bear sightings during our week in Yellowstone NP. The first was a pair of black bear cubs just south of Tower Junction. Another person saw the mother and three cubs and gave us directions, but we only saw these two. We saw the bear in the above photo as we drove by, with a ranger hurrying us along. We pulled over at the next turnout and saw the second cub.

second black bear cub
second black bear cub

Two days later we ran into the same helpful guy, and he helped us see another bear. We were driving through the Lamar Valley, when we saw a lot of parked cars and tripods. We saw the guy who had helped us with the black bears, so we went over and talked to him. He was watching four coyote pups playing up the hill through his spotting scope and taking photos with his 500 mm prime lens. By the time I got set up, the pups disappeared behind the rock.

As the guy was packing up to leave, he asked folks across the road what they were looking at, and they said a grizzly bear. As usual, we couldn’t spot it with our binoculars despite everyone’s directions on where to look, so the guy took his spotting scope back out from his truck and set it up so we could see the grizzly bear. Then we saw the grizzly bear lumbering up a distant ridge! This is where we learned that a spotting scope can transform a puzzled “where?” experience to the “aha!” of seeing the behavior of wildlife. Here’s an uncropped photo of the ridge at 400 mm.

grizzly bear on distant ridge
grizzly bear on distant ridge (click to enlarge)

Here’s a photo cropped to 1024 pixels from over 5000 pixels. The bear is a dark blob in a gap between the trees, near the ridgetop.

grizzly bear walking behind trees
grizzly bear walking behind trees (click to enlarge)

Here the bear is on the ridge line, on the left. Compare the two photos to see that the bear has moved. Everyone said that this is a grizzly bear. I couldn’t tell, but it had to a big bear to see at this distance.

grizzly bear on ridgeline
grizzly bear on ridge line (click to enlarge)

On our last day in Yellowstone, we saw this black bear cub just south of the Upper Terraces near Mammoth. Note that black bears aren’t always black; they can have brown or cinnamon coats.

baby black bear
baby black bear (click to enlarge)

Below, the sun came out for a bit. I like this next photo, with the sun behind the bear, highlighting its back, head, and paw. I take no credit for the backlight — I simply walked closer to the bear, keeping my back to the road with cars and people, in case the momma bear discovered us. The sun came out from the clouds behind the bear, and I took the shot.

black bear
backlit black bear (click to enlarge)

The cub tried to ignore the crowd of people taking pictures. Everyone stayed on this side of the trees. But if the cub or its mother, who never appeared, had charged us, it would have been a mess. The photo below was taken at 100 mm, to show the folks closer than me. The other photos of this bear were at 400 mm without a tripod, and some of the photos are cropped. Occasionally I can get a sharp image without a tripod, but the rate of keepers is much higher when I use a tripod.

taking photos of bear
taking photos of bear (click to enlarge)

We planned to hike in both national parks, but we stayed to well-traveled trails because of concerns about bears. The local couple we talked with at Schwabacher’s Landing carried several cans of bear spray, and they cautioned us about hiking too far away from everyone else. They’ve had to use bear spray. The Colorado guy who helped us in Lamar Valley also carried bear spray. Years ago, he and his brother were fishing when a black bear kept approaching them, perhaps after the trout they had caught. His brother threw rocks at the bears, and the bear finally backed off after getting hit by a good-sized rock. So two sets of regulars to the parks both carry bear spray based on their personal experience with bears. A can of bear spray costs $50 and can’t be taken on US flights, so we didn’t buy any and therefore stayed away from trails with bears.

For folks who want to see bears in Yellowstone, go before mid-June, when the weather warms up and the bears in their bearskin coats head for the cooler high country. We heard this from the ranger who told us about the osprey nest and from the Colorado guy, who has visited Yellowstone dozens of times.

Yellowstone: Hawks

This is part of a series of posts about wildlife we saw in Yellowstone National Park during our June vacation in Grand Teton and Yellowstone National Parks.

In the Lamar Valley we saw hawks soaring above us. Above is a photo of an adult red-tailed hawk — my best photo of a red-tailed hawk so far. On vacation, I had the camera with telephoto lens in the car. The tail of the adult hawk is orange. btw, all three photos here are 400 mm and cropped so that the birds are larger. You don’t get to choose the altitude that hawks soar at.

We were excited when we saw the below pair of birds soaring in the Lamar Valley — we thought they were adolescent bald eagles. Adolescent bald eagles have brown heads — bald eagle heads don’t turn white until they are about 4-5 years old. Looking at bird photos at our apartment, then we thought that they were golden eagles.

Swainson's hawk
Swainson’s hawk
Swainson's hawk
Swainson’s hawk (click to enlarge)

However, when friends who are birders, saw the photos, they identified the birds as Swainson’s hawks, because of the barred tail in the last photo, with the white leading edge of the wings and the black flight feathers (trailing edge).

Yellowstone: White Pelican

This is part of a series of posts about wildlife we saw in Yellowstone National Park during our June vacation in Grand Teton and Yellowstone National Parks. The American white pelican is a large, white aquatic bird that breeds in the interior of North America. Pelicans have a large throat sac to store fish that they catch. Although the population of white pelicans declined in the mid-20th century due to shell thinning (DDT) and habitat loss, the white pelican rebounded and is now stable. The above pair of white pelicans is climbing out of the Yellowstone River after fishing. They then proceeded to take a nap. The four pelicans below were soaring above the Hayden Valley.

white pelicans in flight
white pelicans in flight

We watched these six pelicans fish together at Pelican Creek. Unlike the brown pelicans that inhabit the California coast and dive for fish, white pelicans hunt for fish while swimming. White pelicans hunt cooperatively, forming a circle to corral the fish and then ducking their heads to fish at the same time. Here they duck their heads at the same time.

white pelicans fishing in unison
white pelicans fishing in unison (click to enlarge)

And two seconds later, they come up together.

six pelicans coming up
six pelicans coming up (click to enlarge)

Being large and heavy, it takes time for a pelican to take off from the water. Here two pelicans are taking off, stepping on the surface as they take off.

white pelicans taking off
white pelicans taking off (click to enlarge)

All our pelican sighting were in the Hayden Valley or Pelican Creek where it joins Yellowstone Lake.  All photos were at 400 mm.