Craters and Cinder Cones

Four days cycling and camping in Northern Arizona’s monumental, under-appreciated volcanic region

Sizing up Shit Pot Mountain. (Yes, that’s actually what it’s called.)

alfway between the Grand Canyon and the red rock monuments of Sedona, there is a different kind of geologic wonder, a landscape primarily shaped not by rivers or eons of erosion but by volcanoes. The San Francisco Volcanic Field covers an area the size of Delaware and contains more than 600 volcanoes, from small, hill-shaped cinder cones, to the towering San Francisco Peaks.

I was there last April, pedaling my bicycle up the western flank of a volcano called Kendrick Peak. The volcano towered over the Coconino Plateau, rising to more than ten-and-a-half thousand feet above sea level. I’d spent the better part of the day watching it loom larger and larger as I navigated a labyrinth of gravel roads through a hot, dry landscape of stunted trees and yellowing sagebrush.

It was late afternoon now, and the higher I climbed up the peak, the cooler it became. I passed through a forest fragrant with pine trees — tall, thick-barked ponderosas and, higher up, long-lived bristlecones, with their gnarled and twisted trunks. There is reportedly a bristlecone pine near the summit that is at least 4,000 years old.

Soon the forest thinned revealing a sweeping view to the northwest. An empty plain, dusty and golden in the late light, broken here and there by low, rounded hills, like islands in a calm, yellow sea. No ordinary hills, these were volcanoes. Cinder cones, piles of volcanic debris that formed when molten lava erupted skywards and rained back to earth as solidified rock. I rode by dozens of them that afternoon, many of them overgrown and eroded, unrecognizable as volcanoes. They had the simple, unembellished place names typical of the west: Horse Trap Hill, Red Hill, Red Mountain, Sheep Hill, Connors Hump.

View from Kendrick Peak. Somewhere beyond the horizon is the Grand Canyon.

I was here on a one-week vacation to ride the Craters and Cinder Cones Loop, a 150-mile bikepacking trail through the San Francisco volcanic field. Consisting of gravel Forest Service roads and rocky double-track trails, the bicycle route passes through a surprisingly wide range of habitats, from ponderosa woodlands to high desert plains and sub-alpine forests. But the landscape’s defining feature is its volcanoes. Volcanic activity began in this region over 6 million years ago and continues to this day. While there hasn’t been an actual eruption in 1,000 years, it is all but certain that the volcanic field will see one at some point in the future.

At the top of the climb, I rode into a level meadow nestled between two ridges with the snow-dusted summit as a backdrop. I unpacked a tent from one of the bags strapped to the bicycle frame and set it up amid dry tufts of grass and hardened cowpats. I boiled water on a small propane stove and prepared my dinner: rehydrated spaghetti and meatballs. An Uber driver had warned me about bears, which I didn’t think I needed to worry about in Arizona. But I hung my food bag from an overhanging tree limb just to be safe.

I had flown into Flagstaff two days earlier. I spent an afternoon in the parking lot of the local REI reassembling my bicycle, which I had mailed ahead from my home in Oakland. The Loop begins and ends in an assuming neighborhood park on the west side of Flagstaff. Day one was long and uneventful as I cycled out of the city and into Coconino National Forest, a landscape of high mesas and dense ponderosa forests. The gravel roads were well-maintained and dry. It would have been smooth, easy riding, if not for the high elevation, which left me in a constant state of breathlessness. I ended up doing 50 miles that day, but it felt like 100.

You can’t truly appreciate the San Francisco volcanic field until you’ve seen it from above. From this vantage, the volcanic craters, or calderas, are clearly visible.

I started day two with a flat tire. This was followed by a delay leaving the town of Williams, to which I was forced to return after realizing I’d forgotten to refill my water bottles. From Williams I headed north into the most remote section of the Loop. No towns, services or paved roads for the next 100 miles. No tree cover either and therefore no escape from the heat. It was approaching 95 degrees.

Now, in the meadow atop Kendrick peak, the temperature was plummeting. The sun had just gone down and it was already below 40. I put on every scrap of clothing I’d packed and hunkered down in my sleeping bag. It was barely eight o’clock. I started reading a book, for which I’d set aside precious packing space, but it was hopeless, I was exhausted. Within minutes I was sound asleep.

have been going on long bicycle trips for almost a decade. In the summer of 2014, after four years trying to make it in the New York advertising world, I quit my job and spent three-and-a-half months riding alone across the United States, from Connecticut to Seattle, then south along the Pacific Coast to San Francisco. I rode through eleven states (and one Canadian province), crossed the Continental Divide five times, and, in all, covered a distance equivalent to a non-stop flight from LAX to London Heathrow. The Craters and Cinder Cones Loop, a four-day ride of less than 200 miles, might seem to offer little challenge by comparison. And yet, in many ways, it has been my most daunting adventure to date.

Somewhere in northwestern Wyoming, from my 2014 cross-country bicycle trip.

There was the altitude. The volcanic field rests on the southern margin of the Colorado Plateau and averages 7,000 feet above sea level. My route would eventually take me over 9,000 feet. There was the fact that the loop consists almost entirely of gravel roads and trails, which would test for my limited bike-handling skills. Much of the volcanic field is wilderness or empty rangeland, remote, inaccessible and off the grid. If I had a breakdown or some other emergency, I would be on my own. And then there was water. The volcanic field is high desert, and water is extremely scarce in the best of years, and 2018 was a drought year, with record low precipitation the previous winter. The little water I did come across would likely be found in cattle tanks: small, brown puddles of fetid, scum-covered water that even the cows turn their noses at.

To handle the rough trails, I rode a heavy-duty bicycle, with steel tubing and 2.5-inch tires, a rig built for bikepacking. (Bikepacking is a hybrid of mountain biking and wilderness backpacking. Its popularity has skyrocketed in recent years, doing for bicycles and adventure cycling what #vanlife and glamping have done for RVs and camping.) I carried my gear in specially-designed bags mounted directly to the bicycle frame, a set-up that’s lighter and more streamlined than the pannier and rack systems of traditional road touring. I had packed a tent, a sleeping bag and mat, some warm clothes, a first-aid kit and bicycle tools, plus enough freeze-dried meals and granola to last me five days. I could carry up to six liters of water, and had a lightweight filter, which I could only hope would render the scum water drinkable.

Everything I need for a four-day adventure.
A typical Northern Arizona cattle tank.
One of the “roads” on the Craters and Cinder Cones Loop.

I was well-equipped and prepared, yet I still felt anxious, even as I set up camp that second night. I was more than halfway through, only 70 miles and two days to go. I had a good supply of water left, and there was a reliable spring just a few miles down the other side of the mountain. My body was holding up, even my iffy knees, which had prematurely ended more than one bicycle trip. Everything was going according to plan.

hen I woke the next morning, my tent and bags were covered in a crystalline frost, and the water in my Nalgeen had frozen solid. Twenty-five degrees, read the thermometer. (Oddly, as cold as it was, I couldn’t see my breath, a sign of how dry the air was.)

But the overnight freeze had another, more serious consequence, which I only discovered later that morning as I attempted to filter water from the spring. The filter, a bulb-shaped pump with a long hose, wouldn’t draw water. It took me a couple minutes to realize what had happened.

The filter was frozen.

This was more than an inconvenience, or a matter of waiting for it to defrost. The filter operated by forcing untreated water through a set of narrow, capillary-like fibers. If water in those fibers freezes, it can rupture them, rendering the filter useless. I had no way of telling whether the fibers in my pump had ruptured or not. But I could no longer trust that the water passing through it was in fact safe to drink.

Trying not to panic, I took stock of my remaining water supplies. A liter and a half. How long could I make that last? Half a day, maybe? The next drinkable water source was in Sunset Crater, a full day’s ride away. I would have to boil the water. I should have done that right then and there, but I still hadn’t warmed up from the previous night and was eager to keep moving. So I refilled my empty water bottles with the suspect cattle tank water and kept riding.

It was all downhill from there that morning. I mean this literally. The meadow where I had camped was 8,000 feet above sea level. By noon I was riding through a dusty, dry basin below 6,000 feet, the lowest point of the trip. The landscape was flat and barren, the only volcanoes I could see were huddled on the horizon. The tallest of these were the San Francisco Peaks. Visible from every corner of the volcanic field, the San Francisco Peaks are the remains of an immense stratovolcano, like those found in the Pacific Northwest. One of the peaks reaches a height of 12,367 feet, making it the highest point in all of Arizona.

The trail turned to a corrugated gravel road as wide as a freeway.

The trail had turned into a corrugated gravel road as wide as a freeway. Herds of cattle roamed freely across land that seemed more dirt than grass. The route had strayed onto the Babbit Ranch, a 120-year-old ranching operation owned by the family of former Arizona Governor Bruce Babbitt. I later learned that the Babbitts own more land in Arizona than any entity other than the government itself. Fortunately the roads and trails running through the ranch remain open to the public.

That’s the thing about the San Francisco Volcanic Field. Geologically it’s one place: the volcanoes and lava fields all originate from the same hotspot in the Earth’s mantle. But geographically, politically, functionally, the field is many overlapping, sometimes competing, domains. Portions of the San Francisco Volcanic Field are owned or otherwise managed by two National Forest districts, a private ranch, two National Monuments, the state of Arizona, and the city of Flagstaff. In a different part of the country, like California, the entire volcanic field might have been a national monument in its own right. Such a designation seems more unlikely than ever, as Federal lands in the West are increasingly under threat from those who should be fighting to protect them.

For what it’s worth, the system here appears to be working, at least from an outsider’s perspective. All parties involved seem to be getting most, if not all, of what they want: the ranchers can graze their cattle; the conservationists have Sunset Crater and Wupatki Monuments, preserving natural ecosystems and historic spaces in close-to pristine condition; and recreationists like me have ample access to explore, bike, camp, hike, hunt and fish in these lands. If the Federal Government is no longer going to protect lands in the West, perhaps this patchwork approach to land management is the next best alternative.

In the foreground, private ranch land. In the background, Humphrey’s Peak, part of the Coconino National Forest

After crossing the dry basin, the Loop makes a 90-degree turn and starts heading south back toward Flagstaff. The cinder cones I encountered here were younger, better preserved and clearly volcanic in origin. It was here that I encountered the field’s most colorfully-named cinder cone: Shit Pot Mountain, modestly abbreviated S.P. Mountain on most official maps. The rim of the crater is encrusted in black andesitic rock. When viewed from above, the dark rim and the equally dark lava flow trailing away to the north, resemble nothing so much as a chamberpot overflowing with excrement.

True-color satellite image of Shit Pot Crater (center). The black “overflow” to the north is a lava flow that extruded from the base of the cone. Also pictured is the enormous, dish-shaped Colton Crater (lower center). Source: Google Earth.

The guides I’d read recommended a side trip to the top of the mountain. What I thought would be an easy hike up a maintained trail turned out to be a vertigo-inducing scramble straight up the nearly vertical slope of the cinder cone. The volcanic gravel was surprisingly, alarmingly loose, like a pile of dry beach sand, and I had visions of the slope collapsing, burying me in a gravel avalanche. The views of the crater’s interior were underwhelming to say the least, though I did get a good view of Colton Crater, an impressive, dish-shaped caldera to the south. Going down was even harder than going up. I lost the path and ended up on an even steeper slope, with gravel so loose I sank down past my ankles. When at last I made it to the bottom, I was so relieved to be on solid ground that I had the urge to bend down and kiss it. After pouring a small cinder cone’s worth of gravel out of my shoes, I got back on my bike and kept pedaling south.

Herds of cattle roamed freely across land that seemed more dirt than grass.

I was 30 miles away from Sunset Crater when, with a final gurgle from my CamelBak, I ran out of water. I had put off boiling the water I’d collected that morning, hoping against reason that I’d be able to make it to Sunset Crater and save myself the hassle. Now I would have to stop in the middle of nowhere to boil water under the mid-day sun.

As I rummaged through my frame bag, my hand found my first aid kit. And suddenly it hit me: there was another, easier way out of my water dilemma. The previous August I went on a backpacking trip in Zion National Park with my girlfriend. At the time we’d had the good sense to buy a little bottle of iodine tablets as a backup for our filter. Now, opening the first aid kid, I found that same bottle of tablets. Thirty minutes later I had four liters of brown, chemical-scented but otherwise clean drinking water. Energized by this stroke of good luck, I pushed through the final leg of the day, coming within 35 miles of Flagstaff and the end of the trip.

he final day of any bicycle adventure is often the hardest, no matter how many miles have been and are left to be cycled. It is, like much of bikepacking, a mental rather than physical challenge. Your mind gets ahead of you, racing out to the end of the journey, when you reach your final destination, and the resolve and focus and suffering it took to get there are shed like a travel-worn pair of boots, replaced with that sense of achievement and relief that comes at the end of any long journey. Mentally, you’re done. You’ve changed out of your dusty trail clothes, folded up your map for the final time, and are about to enjoy a big, juicy hamburger with an ice-cold bottle of Coke. Meanwhile, you, physical, actual you, has just woken up in a tent somewhere that is not your destination, with the final miles of your journey still to be ridden.

In my case, the tent I woke up in was situated on a hill of black sand just outside of Sunset Crater National Monument. The “sand” — a slightly finer grind of the cinders I encountered on Shit Pot Mountain — originated from Sunset Crater, a rust-colored cinder cone that last erupted in 1090 AD, making it the youngest volcano in the field. Instead of piling up in a neat cone, the cinders were spewed across the landscape, covering hundreds of square miles. Incredibly, a forest has already begun to recolonize the area. The cinders serve as a kind of rocky mulch, shielding a damp, nutrient-rich soil.

The black dunes make for a dramatic landscape, but they’re hell to ride a bicycle through. (The locals seem to prefer ATVs, judging by the tire tracks criss-crossing the forest.) My 2.5-inch tires sank right into the soft trail, and I was forced to dismount and push multiple times. I was actually relieved when the trail finally ended and I turned onto the paved entrance road to the National Monument. The road meandered through the Bonito and Kana-a lava fields, vast, otherworldly tracts of jagged, black basalt piled up like the rubble of Sauron’s fortress in Mordor. The landscape so resembles the surface of the moon that Apollo astronauts used it as a training ground.

Part of me would have loved to spend some time off the bicycle exploring the monument, hiking through the lava fields or to the top of the crater. But after three days of riding, covering nearly 150 miles, pedaling, and all-too-often pushing, through deep gravel or up steep mountain slopes, fighting headwinds, and all the while sustaining myself on granola, freeze-dried pasta and a couple hunks of salami, I was exhausted, drained of nearly all my energy, and a good deal of my enthusiasm. I was over it.

Unfortunately I still had one obstacle standing between me and the finish line in Flagstaff: the San Francisco Peaks. After circling the mountain range for days, the route now turned toward it. There was an easier way. It involved riding on the shoulder of Highway 89, but it would have saved me 4,000 feet of climbing. Lord knows I was tired enough to consider it. But then I pictured myself back at the office in a week’s time, staring out the windows at the green hills across the San Francisco Bay, wishing I could be among them riding my bicycle. There would be plenty of time for rest. I was here to ride.

The approach to the climb was from the east, giving me a view straight up the long, narrow valley that leads to the snowbound Kachina Peaks Wilderness. The valley is evidence of an ancient cataclysm, a Mount St. Helens-like lateral eruption. On a map, or from a plane, it’s easy to see how the basin is actually a giant crater with one side blown out. More than one Native American tribe considers the sub-alpine wilderness within the basin to be the realm of the gods. Today it’s part of a ski resort.

After a relatively flat warm-up, the gravel road turned sharply upwards and started switchbacking up the mountainside. These were by far the steepest grades of the trip. “Not maintained for passenger cars,” a series of signs warned. Every time I thought I was near the top, there would be another switchback, and the climb would continue. But the view. The higher I climbed, the more of the surrounding landscape I could see. You can’t truly appreciate the San Francisco volcanic field until you’ve seen it from above.

The road terminated at a high mountain glade, but the climbing was only just beginning. I headed deeper into the Kachina Wilderness via a steep, narrow singletrack trail. The air had a crispness to it that reminded me of trips to the Sierras. I had climbed through several biomes, from grasslands, to pine forests, and eventually into a sub-alpine aspen forest. The pale, straight trunks of the aspens growing so close together was disorienting. The grove felt slightly haunted, and I could see how previous visitors could think it sacred. I remembered that aspen groves like these are often a single organism, a forest of clones, each tree an offshoot from the same root structure. It was still too early in the season for the aspens to have any foliage. I could only imagine how beautiful the grove must be in autumn when the trees are decked in crowns of gold.

And then, with one final switchback, I was at the top. It was still 20 miles to Flagstaff, but nearly every one of those miles was downhill. And what a descent it was. A steady -5% grade, smooth, non-technical gravel, and epic views the whole way down. In some sections, snow lingered at the margins of the trail. In others, storm-felled trees blocked my path, though they were easy enough to get around. I descended through a large burn area, a scar of the 2010 Shultz Fire. It was a post-apocalyptic scene. A year on I still have vivid memories of the blackened husks of dead trees clinging to the slopes, and the sound of the wind moaning through their brittle limbs.

The never-ending descent eventually ended. Soon I was retracing my tracks through the forest outside Flagstaff. The transition back to the real world was abrupt. One minute I was on a dirt road with pine trees as far as the eye could see. The next I was at a busy intersection across from a playground and a baseball field surrounded by houses. I felt like I had been gone for weeks. I was desperate for a shower, and was looking forward to a warm night in a hotel bed. But before doing any of that, I headed to a local brewpub I had seen before I’d left. There was a hamburger and Coke with my name on it.

More About the Route

My thanks to Kurt Refsnider, who created the Craters and Cinder Cones Loop and published the guide and maps I used on this trip. Kurt happens to be a geologist and much of this essay was informed by a guide he and his colleague Kaitlyn Boyle wrote. For more information about the Craters and Cinder Cones Loop, check out Kurt’s complete route guide at

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