May 25th - Day 1 exploring Yellowstone
"It's a bunch of holes, all different shapes and sizes!" exclaimed a women with a thick Brooklyn accent who was sitting beside us as we waited for the Old Faithful geyser to errupt. She was right, Yellowstone is full of all sorts of holes, in fact it has more volcanic holes I.e. geysers, hotsprings, and fumeroles than the rest of the world combined!! This is because much of Yellowstone exists within an active volcanic caldera. About 631,000 years ago the Yellowstone volcano exploded in a catastrophic way, destroying the overlying mountain range and leaving behind a flattened landscape for glaciers, rivers and continued volcanism to shape into what we see today. Camped at Maddison Campground our first night in the park, we looked out at cliffs marking the outer rim of the caldera.
Leaving Madison, our first stop in Yellowstone was the paintpots, an area where light coloured, clay rich mud bubbles and sloshes with the consistency of opaque paint. I ended up staying with our bikes, protecting them from a crafty raven who could open zippers to access snacks, while Heather took a few minutes to explore.
Small geyser by the clay paint pots
While I waited, I read about what makes the Yellowstone hotspot unique. In contrast to the hotspots creating the Hawaiian and other ocianic Islands, the Yellowstone hotspot passes through thick continental crust. Since the rock composition of continental crust and oceanic crust are different the material melted and then extruded by these volcanos is also different. The continental crust is dominantly composed of felsic rock, rich in feldspar and quartz, so in Yellowstone there is a lot of rhyolite, a feldspar and quartz rich rock (similar to granite but cooled on the surface). In contrast, the Hawaiian Islands are formed from basalt, a mafic rock high in magnesium and iron, because the oceanic crust is dominantly composed of those dense minerals. That isn't to say that the Yellowstone hotspot couldn't errupt and bring mafic rock to the surface, in fact it has in the past since that dense mafic rock underlies the less dense continental crust. However, in its more recent eruptions, the Yellowstone hotspot has erupted rhyolite. The rhyolite is what gives the ground a white colour here at the paintpots and it is also what gives the mud its smooth paint-like texture. As I mentioned, rhyolite is feldspar-rich and when feldspar is altered, it becomes clay.
The next stop on our loop through the park was Biscuit Basin, an expansive colourful hotspring. The colours are created by an assortment of cyanobacteria. The temperature of the water can dictate the type and colour of cyanobacteria. In waters between 50 and 60 degrees Celcius, where iron is present, you get rust coloured bacteria called chemotrophs. Meanwhile, in water 38 to 56 degrees celcius, you get green phototrophs.
Chemotrophs at the Black Sands Basin
A few more kilometers of pleasant riding brought us to the iconic Old Faithful. We waited in anticipation, along with a swarm of other tourists, as Old Faithful bubbled and then shot water 30-55 metres up into the air. We also got to watch The Grand Geyser errupt. It is the tallest predictable geyser in the world and can spew up to 61 metres high and only errupts every 4-8 hours. These geysers are created as a result of ground water getting supper heated by the underlying magma. As the bottom water turns to steam it creates enough pressure to push the overlying water up to the surface in an abrupt natural fountain.
The Grand Geyser
After a quick lunch at the Kepler Cascades and a slog up and over the Continental Divide (twice), we stopped at my favorite destination of the day. Here at the West Thumb Geyser Basin we got to experience various hotsprings and geysers against a backdrop of Yellowstone lake, distant mountains and grazing Elk!
The second time up to the top of the Continental Divide in one day
View of Yellowstone lake and distant snowy peaks
We camped at Bridge Bay. The campground lies in an open area a bit too far back from the lake to be scenic. I'm not sure why they put the campground here where it doesn't offer any views or many trees for shelter but, it was open and that's what matters. Some fellow bikers who we had met the night before at Madison Campground came and shared our fire. Heather and I are really enjoying each other's company but it was nice to talk with some other people for a change.
May 26th - Day 2 exploring Yellowstone
We were lucky enough to wake up to another beautiful day! Perfect for our second 100km day with many striking sights to see along the way.
Our route took us through Hayden Valley, an open grassland where we were told to keep an eye out for wolves. We didn't find any but it was still one of my favorite sections of biking so far!
Next up was Yellowstone Canyon and it's thunderously stunning lower falls. I could have stood there all day.
View of the “Grand Canyon of Yellowstone”
After lunch and icecream in Canyon Village, we rolled on to Norris. At one point taking a sneaky side route on a road that wasn't open to cars yet.
Norris was beutiful and even if you have already visited a plethora of volcanic "holes" like we had, it is well worth the stop. With the most acidic pools and geysers, walking through Norris felt like walking on another planet.
Norris Basin
Green phototrophs in the Norris Basin
Heather set a mean pace the rest of the way back to West Yellowstone. We cruised the dominantly downhill ride, drafting as we fought the headwind. I'd tuck down low peddling hard on the ups and almost as aggressively on the downs. The wind catching my clothes and carrying the tune of Heather singing Tacy Chapman at the top of her lungs. Our well oiled machine only slowed when we came across car, after car, after car, pulled over on the side of the road. At first I expected the usual culprits, Bison, but as we got closer we heard whispers that there was a mama grizzly and two cubs. Our first grizzlies along our route following a wildlife corridor that is so integral to their wellbeing!
Mother Grizzly and one of her two cubs
Although we saw most of our sights in Yellowstone in two days, we actually spent 5 days in the park and West Yellowstone. We enjoyed some down time at Maddison Campground when we first arrived. We also had the unexpected opportunity to go back into the park with Alison, one of Heather's friends from Invermere. Alison drove us up to Mammoth for the day and we got to check out the Mammoth Hot Springs.
Amaya and Heather in front of the Mammoth hot springs
The Mammoth hotsprings are underlain by limestone. As the hot, carbondioxide rich water passes through on its way to the surface it dissolves the limestone and redeposits the calcium carbonate on the surface as travertine. You get this terracing effect because as the water passes over the lip there is a release in pressure allowing the calcium carbonate to precipitate. How wonderful would it be to be a miniature version of yourself, soaking at the edge of one of these natural infinity pools!
Overall, I have been blown away by Yellowstone. I had been here once before as part of a geology class but traveling by bike and being able to move at my own pace gave me a whole new appreciation for the area. If you had just one of the a) abundant wildlife b) the volcanism or c) the rivers with their canyons, this place would be worthy of being a park. Yellowstone, it has been a delight, although I could have done without the snow on our last morning here.
Much love, Amaya