The Upper Geyser Basin...

The world-famous and uber-popular Old Faithful Geyser sits in the Upper Geyser Basin (UGB), at an altitude of 2240m, in a high point of the supervolcano caldera, and in the south-west quarter of Yellowstone National Park, bisected by the Firehole River. In this spectacular zone of hydrothermal activity, Old Faithful is itself nothing special, it is not the tallest or largest, but it is very regular in its eruption schedule, and the 1900 vintage Old Faithful Lodge is positioned right in front of it.

Old Old Faithful Inn is the classic accommodation choice in Yellowstone, but it's only open in summer.

Between eruptions, Old Faithful puffs steam, sometimes not so much.

One look at Old Faithful, and you just have to wonder what is underneath! What arrangement of plumbing causes its eruptions? Why are they regular? Why are they not perfectly regular? Numerous formal and hand-written signs predict the time of Old Faithful's next eruption, and the claimed accuracy is plus or minus 10 minutes. We couldn't really establish where these predictions come from, and in particular, whether the prediction for the next one is dependent on the actual time of the previous eruption or how long it lasted. But there is ample historical data available. Intervals between eruptions have been between 40 and 125 minutes for 20 years. There's a bimodal distribution of waiting times, with one cluster covering 45-60 minutes, the other 70-90 minutes, and, significantly, longer waiting times produce longer eruptions, (2 and 4.5 minutes respectively). Average waiting times are slowly getting longer - it was 66 minutes in 1939, but nowadays it is a highly predicatble 90 minutes. It's said that this slow-down is partly due to "abuse" by visitors throwing stuff into the geyser's vent. Early visitors did their laundry in the vent!

Crowds gathered as the predicted time for an Old Faithful eruption approaches.

A kind passer-by took this pic of us waiting for the next scheduled eruption of Old Faithful.

This pine, said to be the most photographed tree in the Park, gives scale to steam venting from Old Faithful Geyser.

Old Faithful's eruptions are quite modest compared to others. Boilng water shoots vertically up to 30-60m in the air, and then steam blows off according to the wind direction. We saw other impressive eruptions in the Upper Geyser Basin - one was at a distance from Grand Geyser, the tallest predictable geyser (60m every 7 to 15 hours), and the other was Castle Geyser (25m every 10-12 hours) where we were on the spot!

Grand Geyser has the largest cone in the Upper Geyser Basin.

Near Castle Geyser, a footbridge crosses the Firehole River.

Castle Geyser only erupts twice a day. It has the broadest cone of any geyser in the Upper Basin.

Thus we discovered that Old Faithful's eruptions were not that spectacular. Steam is venting all the time, with the intensity increasing at the eruption. Stand in the wrong place and the wind blown steam plume can obscure the eruption altogether! So, to capture something different, we decided to try some eruption photography at night. There is no lighting on the geyser, so exposure times were 30 seconds, and hands were frozen. Standing to the east of the geyser, with a moderate wind from the north, the steam plume creates a magical fan from right to left. The view is almost the same during the eruption, except the vertical blast of boiling water comes starkly into focus. And we even caught some shooting stars!

The vertical eruption of boling water is clear, then the extra steam is blown away by the wind.

Like a boiling kettle, Old Faithful emits steam between eruptions. Here, a few minutes away from an eruption, steam is taken off by the wind.

Yellowstone National Park has about 10,000 geothermal features, with the highest concentration in the UGB which boasts a network of boardwalks allowing us to walk around in relative safety (people have did getting to close to thermal activity, and as mentioned in our previous blog post, the boardwalk did not protect us from being harassed by bison). Several walks around were very worthwhile with there being many photogenic sights to be seen, as our images will attest. Starting early in the morning, it was -23C, so rather chilly!

We walked all around this region of the Upper Geyser Basin as far as the Morning Glory Pool.

Old Faithful geyser venting steam as it builds up to an eruption.

Eerie and mysterious is this artistic mudpot in the Upper Geyser Basin.

Looking towards the morning sun in the Upper Geyser Basin of Yellowstone National Park.

Many hot springs in the Upper Geyser Basin are named, not sure what this pretty one is called. Castle Geyser can be seen in background left.

Under threatening skies at dawn, bubbling pools and springs of the Upper Geyser Basin drain into the Firehole River.

Hot water from Liberty Pool flows into the Firehole River.

Early morning view over a vent in the Upper Geyser Basin.

Appearing to have twin vents, the Riverside Geyser sits right on the edge of the Firehole River.

Good temperature for a brisk walk around the Upper Geyser Basin.

In the UGB, there over 500 hydrothermal features, of which 130 are named, but one most interesting is Morning Glory Pool which used to be beside the main road to Old Faithful, and thanks to its convenient access, suffered vandalism, blocked vents and cooling from thrown-in trash. Vandalism was eventually controlled by relocating the road!

This bison near Norris Pool seems to like the warmth of the Yellowstone thermal activity, but possibly there is just less snow there, and it's easier to forage.

This bison ponders crossing the Firehole River near Morning Glory Pool, but soon decides against it, and wanders into the scrub.

Beautiful Morning Glory Pool was named in the 1880s but its proximity to the then road led this beautiful pool to suffer vandalism where coins, trash, rocks, and logs were thrown in, contaminating it and blocking its vents, cooling it. Yellow is bacteria that formerly coloured only the periphery of the spring now spreads toward its center. The road was moved away from Morning Glory to save it.

We stayed two nights at the Old Faithful Snow Lodge (1999), about 100m from the geyser and which, although recent, is designed in a classically opulent lodge style. With the Mammoth Hot Springs Hotel closed for renovations, the Snow Lodge is the only accommodation open within the park in winter. Accordingly, it was crowded woth groups like ours and individuals, and the one restaurant was hard to get seated in. Despite its name, the Snow Lodge is open year round. We had a very comfortable ground floor room, no TV, facing out to an ice skating rink.

Our abode for two nights was the Old Faithful Snowlodge (1999)

Warming up in the cosy Firehole Lounge in the lobby area of the Snowlodge.

Big carpark and a flyover make for a terrifying vision of Old Faithful in summer!

More Yellowstone images here.

Towards Old Faithful...

Yellowstone National Park is visited by over 4 million people a year, the vast majority in summer, when a mere glipse of a critter brings gridlock in the traffic. Winter was our preference for this reason. Even in winter, when most roads are closed to all but over-snow vehicles, there were still a good number people and vehicles about, and our accommodations were surprisingly quite crowded with guests.

The hotel at Mammoth Hot Springs was closed for overnight guests, but we were able to go into the lobby areas and even buy a cappucino!

To venture more deeply into the Park, we had to travel over unploughed snow covered roads. At Mammoth Hot Springs we swapped our Mercedes buses for two huge Ford over-snow trucks, very luxurious inside, with gigantic underinflated tyres which are, apparently, more efficient than tracks. Many of the concessions within Yellowstone (and elsewhere) are operated by privately owned Xanterra as part of their Travel Collection, and these two vehicles were from their fleet of 30 or so. Xanterra provided a capable driver cum knowledgeable guide for each vehicle.

Monster trucks took us into the unploughed snow of Yellowstone.

Our Ford snowbus driver and guide was Laura, here showing a map of the park printed on a teatowel.

On our convoluted path to Old Faithful, high up on the Yellowstone Plateau, we encounted many bison, in small family sized herds. The park's bison are special and precious. The park is the only place in the USA where they have lived continuously since prehistoric times (https://www.nps.gov/yell/learn/nature/bison.htm) and have not been contaminated by inbreeding with cattle. After being hunted to near extinction (for sale, for sport and to starve the Indians), the population of the Yellowstone herds now nears 5,000, supposedly something like their pre-whiteman levels. Bison come down from the highlands to the plains during winter for nutrition which they find by burrowing in the snow, but they are apparently pretty undernourished during this season, and, to save energy, are loathe to move much.

These bison are seemingly unaware of the spectactular late afternoon vista behind them, sunset plus hydrothermal steam.

The bison we saw behaved as predicted, always either lying down resting, or standing and burrowing in the snow, or moving very slowly. We had been warned to stay away from them, but on one scary occasion they approached us in a herd of maybe a dozen when a group of 6 of us were following a boardwalk in the Old Faithful geyser basin, and we couldn't back away. When he was very close, the alpha-male gave us the evil eye and communicated quite clearly which way we should go. We obeyed! The sequence of 5 photos below shows how the herd approached us, then led by the boss, trampled over the boardwalk exactly where we had been standing, and proceeded down to the Firehole River.

As we drove south into Yellowstone, we gained considerable altitude, and it got colder. Put simply, Yellowstone is mostly an elevated plateau averaging 2,400m above sea level (higher than Mount Kosciuszko) surrounded by ranges of the Rocky Mountains up to over 3,000m. It is split by the North American continental divide and is dominated by a supervolcano caldera which encloses about a quarter of the park. The last major eruption was 600,000 years ago, but the underlying heat powers what is now the world's largest field of hydrothermal activity, hotsprings, geysers (hotsprings which periodically erupt to relieve accumulated pressure), fumaroles (a steam vent which does not erupt), mudpots (hotsprings acidified by volcanic gases, like hydrogen sulphide, dissolving rock into mud, aided by micro-organisms) and travertine terraces (type of carbonate limestone precipitated by flowing mineral springs).

View of the travertine terraces at Mammoth.

Our first sighting of hydrothermal activity was before we left Mammoth Hot Springs which is home to steamy but spectacular travertine terraces, including Canary Spring and other named features, so many that we were not quite sure which one was which. But, of course, the real favourite in the hydrothermal department was to be the world-famous Old Faithful Geyser but we had a lot to see before we got there.

Boardwalks approach these steamy terraces with safety.

A terraced waterfall at Mammoth Hot Springs, the multi-colours from agae and bacteria.

Named in 1871 and long extinct, this inactive spring sits in front of Canary Terrace.

Beguiling colours in this hot spring at the top of Canary Terrace at Mammoth.

Our two Drews from National Geographic clearly knew how to get the best from this expedition into Yellowstone - Drew 1, the local resident and expert, and Drew 2, the NatGeo photographer who positioned us precisely for superb landscape shots, and the best views of wildlife like trumpeter swans - we even saw an iconic bald eagle.

Snow blowing on high as we look towards Mary Mountain from the Grand Loop Road.

Listed as endangered, the bald eagle (haliaeetus leucocephalus) raptor is the national symbol of the USA. It likes to nest near Yellowstone Lake, feeding mostly on fish and waterfowl, this one hunting in the Gibbon River.

Once nearly extinct thanks to hunting and habitat loss, the large Trumpeter Swan (Cygnus buccinator) has been saved by conservation measures with 50,000 in the Lower 48, but there are still only about 30 in Yellowstone NP which is a marginal environment for this species.

Enchanting sunset view in Yellowstone's Lower Geyser Basin.

We passed the world's tallest active geyser, Steamboat which is located in the Norris Geyser Basin and near the Gibbon River. Its eruptions are huge, up to 90m in the air, but they are extremely irregular, the intervals between successive eruptions being days (typically) or years (in 1991 and 2013 eruptions broke nine year droughts, and there were none at all between 1911 to 1961). Strange plumbing underneath, it would seem. No predictability here, and we certainly didn't see Steamboat go off, but our snowbus guide Laura said that she was camped nearby for a long period during her undergraduate study years and was lucky enough to see it go up. Steamboat's last eruptions was only a few days before our visit, at 12:35 on 25Jan2019. Images of Steamboat eruptions can surely only be got by patient or lucky photographers!

Great shot of Steamboat's eruption in August 2018 by BPNJensen (from Wikipedia)

Deep in Yellowstone, there are few public facilities and restrooms, but luckily our guides knew where they all were. Secreted in the back of our snowbuses were packed lunches that we had ordered several days previously (so what we got was a surprise), and we ate them at locations like Canyon Village and Madison, both intersections in Yellowstone's sparse road system.

This team of local characters are apparently fully occupied removing accumulated snow off YNP rooves.

Just off the Grand Loop Road, near Paintpot Hill, one of a multitude of hot springs in Yellowstone.

Near Canyon Village is the Grand Canyon of the Yellowstone, the river that gives its name to the National Park and is itself named for the colours of rocks in the river or sandstone in the bluffs nearby. Here, the Yellowstone River flows and falls in a spectacular gorge, and from the appropriately named Artist Point, offers a fantastic view, summer or winter. The Yellowstone River which actually starts in northwest Wyoming is, at 1107km, the longest undammed river in the "lower 48". Quite separate to the Yellowstone River but still east of the Continental Divide is the Gibbon River which runs into the Madison River, then the Missouri River near Three Forks, MT and eventually the Mississippi River near St Louis, MO.

From the aptly named Artist Point, a spectacular view of the Yellowstone River.

Not the grim reaper! Updrafts from the Yellowstone Canyon below chill visitors walking to viewing points.

The headwaters of the Yellowstone river proceding towards the falls and canyon.

We saw many snowmobile tours in Yellowstone, all were quiet and orderly no doubt as enforced by guides and rangers.

Known by 1872, the falls on the Gibbon River are upstream of its junction with the Firehole River.

At dusk on day three of our expedition we finally arrived at the Upper Geyser Basin, on the Firehole River and the site of Old Faithful. See our next blog post for that story.

Summer postcard of Old Faithful and a hot spring. Not like this for our visit! And where are the people?

More of our Yellowstone images here.