Monday, September 16, 2013

Into the Great Unknown: Heat...and All Things Beautiful

It was our last full day on the Colorado River through the Grand Canyon, the Great Unknown as John Wesley Powell called it in 1869. One full day, and one more night on the life-giving stream of water through one of the spectacular canyons on Earth. We had eighteen miles to go, from our camp at Mile 202 to 220 Mile Camp (it was clear that the geographers were running out of names for the features in the canyon; it's that big).

It was a day full of the best things the canyon could offer. But it was also hot. Blazing oven hot. Merciless sun beating down hot. In other words, a normal summer day in the Inner Canyon. The thing is, we had already experienced a few hot days on the trip, but not quite the kind of 115 degree days that we were warned about in the training materials. I don't actually know how hot it got, but in my memory, it was the hottest day of the trip.

They said a few things in the training videos for rafting the river. To drink before you get thirsty. To drink a gallon a day. To always wear a hat. Seek out shade when possible, and don't hike between 10 and 4. They said it takes a human body about two weeks to acclimate to extreme hot temperatures, meaning a river trip was not long enough to do so.
We were seeing all kinds of adaptations to the heat as we explored the area around our camp during the relatively cool morning hours. We had dropped nearly 2,000 feet during our two weeks on the river, and the desert vegetation was characteristic of the Lower Sonoran Life Zone (or whatever the biologists are calling it these days). Cacti had been rare in the upper reaches of the river, but now they were common.
There were a few shrubs with their characteristic waxy leaves taking advantage of the recent storms by putting out a few flowers.
Best of all were the ocotillos that we had been seeing for the last two or three days. They too had taken advantage of the recent storms, and had put out thin leaves along their green branches (most of their food production happens in the branches rather than the leaves). There were none of the beautiful  red flowers (we'd need to be here in May for that).
We took advantage of the relative cool of the morning to search out some pictographs that were said to be up in 202 Mile Canyon. It took a while (which is why I had given up and photographed the plants instead), but eventually we found them. It was a small measure of the rate of geologic change that some of the blocks of rocks containing the rock paintings had tumbled down from the ledge.
Once the sun reached our boats, we set off down the river. We continued to see remnants of the lava flows that had once produced high dams, and which had continued downstream for many tens of miles (above).
We also saw another gigantic landslide that had involved the entire canyon wall (above). Lava flows aren't the only things that have produced dams on the river. As noted in an earlier post, landslides have altered the course of the river a number of times.
We saw more evidence of human occupation in the canyon. We discovered roasting pits in several of the debris fans at the mouths of some of the tributary streams. Along with the cracked and shattered rocks we found bit and pieces of pottery.
A short hot hike up Indian Canyon offered a fine view up the river. But it was hot and there was no shade. I shiver to thick how quickly I would have been in trouble here had I not been carrying a quart of water at all times. I was drinking at least a gallon and a half of water on days like this, and when it got too uncomfortable, I could splash in the river water to cool off. Despite being 200+ miles downstream from Glen Canyon Dam, the water was still in the mid-to-upper fifty degree range.
The scenery continued on a grand scale, with high cliffs at every turn. We saw another bighorn along the riverbank. It was as if the river was giving us reminders of why the canyon was precious. And that was the way I was feeling. This was the last full day, and while I was wanting to see the people I was missing in the outside world, I was also feeling like I wanted to hold onto these incredible experiences that I felt were enriching and transforming my life.
We crossed the Hurricane Fault again, and the ancient Vishnu Schist was exposed at river level once more.
 In the intense sunshine, the polished surfaces of mica, quartz and feldspar reflected brightly.
 It's amazing what the silt-filled water can accomplish!
 As we searched for (unsuccessfully) for a shady lunch stop, we encountered an unusual looking ledge of Tapeats Sandstone on the left bank.
The top of the ledge had been scoured and eroded by river currents, and it looked recent, yet the bench was 15 or 20 feet high. It looked extremely fresh.
 At the lower end, there was a strange orange-colored edifice called Pumpkin Spring. It was a warm spring deposit that was redepositing travertine that had been dissolved from the overlying limestone formations. The heat probably came from nearby active fault zones. The water was green and uninviting. The river guide suggested not drinking it because of high concentrations of arsenic (is that a poison or something?).
 We set up a canopy and crowded underneath it to eat lunch. There was a hot breeze blowing so the shade barely helped. Unfortunately the wind was trying to destroy the umbrellas that most of the boats had, so there was really no place to retreat from the sun. For pretty much the first time voluntarily, I spent most of the time soaking in the river as long as I could stand it (cold!), then getting out and warming up until I was dry and hot, and then getting back in the river!
Despite the heat, we wanted to check out the unusual terrace in the Tapeats Sandstone that we had just floated by. We grabbed some water and headed back up the canyon. The edge was pockmarked with huge potholes, many of which had carved right through the rock, forming little tunnels and caves. Many of the potholes still had the pebbles and cobbles that had carved them.
It turns out the terrace has been flooded by river water in historic time during the big spring floods, but only rarely since the floodgates of Glen Canyon Dam shut in 1963. The dam is still altering the river, even 200 miles downstream.
 We made one more stop that afternoon, at Three Springs Canyon. Like so many tributaries, it had a small stream of clear water that we could use for drinking. Some of the crew pumped the water filters while others hauled the five-gallon buckets down the trail to the boats.
 Yours truly found he could make a human dam across the trickling creek and have a nice bath.
It was the hottest part of a very hot day, and a hot breeze was blowing up-canyon. No one felt like rowing against the wind, not in the hot sun without the umbrellas. We holed up in the shade behind a ledge at Three Springs Canyon for quite awhile, letting the afternoon shadows extend across the canyon a bit.
 We arrived at our site for the night at 220 Mile Camp. As if to make some kind of point so late in our trip, it was one of the most beautiful camps of the trip. There was an island of Vishnu Schist in the river decorated with a few wispy tamarisk saplings. Our camp was in the shade (relief!), but the sun was shining brilliantly on the cliffs across the way, reflecting on the river.
The view upstream was gorgeous as well. At this late point in the day, no one else was on the river; the feeling of isolated wilderness was complete. It was strange to think that only six miles away a road reached river level, and that we would be driving out of the canyon in the morning.
We drank the last of the beers and the sodas, ate most of the remaining food, and sat in the warm air watching the sunlight drain away from the cliffs as night fell. After a while, a cool breeze wafted off the surface of the water.
The moon was a touch higher in the sky than the previous evening (it always happens that way), but it soon dipped below the cliffs. It was the 11th of August and the Perseids Meteor Shower was scheduled to debut in the night sky. It did not disappoint; as we talked and sang and played the guitar, I counted maybe a hundred shooting stars, some of them blazing a trail all the way across the sky. I had been turning in early on many nights of the trip, but on this night I was still awake staring at the show in the sky until well past midnight. I'll not forget it any time soon. I didn't want the night to end, and yet I did.

Tomorrow we would be back into civilization, and I would be starting the journey home...


Gaelyn said...

Our last full day on the river was a hot one too. But Pumpkin Spring was completely under water. I'm as sad as you that your journey is almost over. Well, I know you're already home. But you know what I mean. Thanks for the memories, and great geology along the way.

Ruby said...

Just wanted to say thanks for the trip down the canyon. I've been following you every morning with the coffee. As an Arizonan who has only seen her from the rim, I'm inspired to find a way down the river someday.

And thanks also for the geology lessons. Can't live here without lovin' the rocks.

Keep posting, I'll keep reading.

Katrina said...

Thank you so much for sharing your trip. I doubt I'll ever have a similar opportunity so hearing about someone else's trip is as close as I'm likely to get.

Garry Hayes said...

Thanks for the kind comments!