Part I: Solo trip or death sentence? • an eclipse on the river • just some regular old symmetry-focused topographic detective work.

On the beach at Sand Wash, I'd been chatting with a dude, let's call him "Guy," about the first expeditions down the Green and Colorado rivers. For over two hours.

"So you're a Powell fella," he'd observed. Our kindred spirits took it from there, as we chatted about books, theories, and favorite tales — all colored by Guy's tendency to swear like a sailor at a spelling bee.

Suddenly, we realized the time, having become so caught up in a shared passion. An eclipse was coming. At Guy's suggestion, my aim was to watch from a symmetrical amphitheater, five miles downstream. He'd spent a previous eclipse there, saying the shadow between dark and light swept across the canyon wall with a startling shimmer. But also, from his own research, he believed this might be the real Sumner's Amphitheater. A spot named in 1869 by John Wesley Powell's first expedition, but possibly placed incorrectly on maps by entirely different personnel during the second expedition in 1871. A looming eclipse, a cartographic controversy, a solo trip for 90 miles down Desolation and Gray Canyons of the Green River? Um, yes, please.

As I was preparing to push off from shore, Guy mentioned a few details about my upcoming run. In what felt like a minute-long sentence, without so much as a hard stop, Guy rattled off the basics about river toilet, firepan, and camping regs, before transitioning to a few warnings:

"There's big storms coming in, so watch out for lightning strikes in the river canyon, not much shelter but you'll probably be fine … be careful when hiking, even a sprained ankle can be a death sentence on a solo trip… hey, a lot of people say never go alone, but I think that's a crock of shit … look, we've had many black bear sightings lately, just don't surprise them and you should be OK … and some of the rapids rearranged during the spring high-water so just keep your eyes open for sneaker holes … oh and watch out for the wild mustangs, they might try to charge you onshore … it's more about you letting them show they've got the biggest balls … just don't show any fear, but don't be overconfident … don't move toward them, but don't move away either … and whatever you do, don't stand still — I can't really explain it."

I gulped. Luckily, I was rowing an insulated rubber raft with a SUP along for some side excursions from camps. Also, I'd sprained my ankles so many times, it's sort of a ligament-free-zone down there. I have a tendency to talk to myself out loud while walking, so that should scare off the bears like it normally does pedestrians. And the wild horses? Grazing on the ridges above, they seemed pretty peaceful. With a wave, I called out to Guy: "No zombies?"

Guy cupped his palm to his ear, then waved.

Checking out the upstream view in Duches Hole, at mile 4.5 below Sandwash, which may be the real Sumner’s Ampitheater.

And I was off! This trip was the final major section in my multiyear project to explore the John Wesley Powell route. And to do it all as a fresh-eyes descent, meaning no one on the trip has seen that section of river before. This gives the trip a real exploratory feel, a bit like the Powell expeditions might have felt, granted much less so. Self-guided first times can also cause hilarious mistakes. Early the first morning of our fresh-eyes winter Grand Canyon trip, I mistook raven shit for toothpaste before ranger inspection at Lees Ferry. I spent a bewildered minute trying to bucket rinse it off the beach. Self-guided trips can also amplify the anxiety of the unknown. Usually I went with small groups of friends, but sometimes I went alone. This week-long class II+ trip, through one of the Powell route's most remote canyons, would be my longest solo yet.

An hour of rowing later, I tied up in the spot Guy had described, grabbed my eclipse "go-kit" (a brown bottled beer), and hiked up a crumbling ridgeline. In a meadow below, a small herd of grazing mustangs glanced up. I inhaled sharply as they began trotting up the hillside toward me. Thinking back on Guy's mentoring, I decided my best course of action was to walk a chaotic and zigzagging course—like I was lost in an airport or evading sniper fire. I dropped in and out of ravines, sometimes moving toward the horses, sometimes away. The mustangs stopped and looked around, puzzled. I think one lifted a hoof to scratch its temple.

The eclipse was soon, the orange-brown cliffs dimming to gray, but one complication. No eclipse glasses. I'd gone to dozens of stores on my drive to put-in, all sold out. The whole trip had been last minute. Only a few weeks before, after casually mentioning my passion project on the Powell route, I'd been hired by FalconGuides to turn it into an inspirational guidebook for the entire route, in full color with plenty of photos. Suddenly, the lone remaining section loomed as a major gap in my explorations. So, I'd grabbed a cancelation permit on a week's notice and driven to Utah. I'd invited plenty of friends as a longshot. As I drove toward put-in, I was still getting messages like "You're not going alone, are you?" No, I'd replied but didn't explain my only companions would be a huge pile of books about the expeditions.

Clouds wafted into the canyon just as the eclipse reached its peak. The beam of shadow and light Guy had described passed with an indefinite glimmer and was gone. As colors returned from a brightening sky, I considered Guy's claims. The naming of the amphitheater is not mentioned in any of the original journal entries of the expedition members. But in Powell's 1875 account, he describes sweeping "around curve after curve with almost continuous walls for several miles." In the previous sentence, he writes, "One of these we find very symmetrical and name it Sumner's Amphitheater." A few years later, the second expedition came down the river, using notes from the first expedition to help create a detailed map. In his 1925 book, A Canyon Voyage, crew member Frederick Dellenbaugh describes standing on a ridge where the river seemed just a stone's throw to either side. What he calls Sumner's Amphitheater "was perhaps one thousand feet high, beautifully carved by the rains and winds."

A Google Maps image of the river bends in question. Duches Hole is upstream, in the upper right quarter of the image. The officially-designated Sumner’s Ampitheater is downstream, center-left in the image.

Standing on a cliff, five miles upstream of the one the second expedition claimed was Sumner's, Guy's alternate amphitheater looked damn symmetrical. The top was completely flat, the geologic strata parallel and mostly cohesive. In the downstream half of the curve, ridgelines began to emerge with pillars and hoodoos at regular intervals. The height was around 500 feet. The next test was to visit the other amphitheater for a little topographic detective work.

Downstream, I rowed for several miles through a second amphitheater and into the third, officially designated as Sumner's. In top-down map-view, this third meander took a more curved course in the river. But from water level, the rim appeared broken and uneven, the ridges crumbly and erratic. On the western side, a whole drainage ravine cut down from rim to river. There was little symmetry about it. Certainly, the inside bend matched Dellenbaugh's description of a narrow neck where one might toss rocks into the river on either side. And the cliffs were taller here, a few hundred feet short of a thousand. Perhaps Dellenbaugh and the second expedition had simply gone to the wrong spot for some reason or mixed the two up in both maps and memory? I continued downstream, finding myself in agreement with the observant Guy at Sand Wash.

The downstream portion of the amphitheater at Duches Hole looks pretty symmetrical to me. Check it out the next time you’re there!

Continue to Part II: A hidden inner canyon • intimate encounters with lightning • imagined conversations with historical figures • the myth of Old Brigham

Read more by Mike Bezemek, who writes and photographs the series Regular Paddler, Remarkable Waters  and, now, Weekend Expeditions for C&K. He is author of Paddling the John Wesley Powell Route and Paddling the Ozarks for Falcon Guides and Twit Lit Classics® for Skyhorse Publishing, a book series which reimagines classic works of adventure literature as tweets for a 21st century audience. Learn more at mikebezemek.com.