Stop and think about this for a second: the Rocky Mountains were formed between 80 and 55 million years ago. They stretch more than 3,000 miles, from the northernmost end of British Columbia down to the Rio Grande in New Mexico. I’m looking at a map, I’ve seen them in person, and I still can’t wrap my head around either of those facts.

Rocky Mountain National Park is in Colorado’s northern Front Range, split from north to south by the Continental Divide. The park hosts over 350 miles of trails, 150 lakes, and 450 miles of streams; of the park’s named mountain peaks, 72 reach more than 12,000 feet into the sky. On the north end of the park, the Mummy Range contains a handful of smaller “thirteener” peaks: Hagues Peak, Mummy Mountain, Fairchild Mountain, Ypsilon Mountain, and Mount Chiquita.

Before I was in Grand Teton National Park, I was in Rocky Mountain National Park’s Mummy Range. That’s where I got the closest to dying that I’ve been all summer. And this is the story of what happened.

Seattle, Washington (Elevation: 518 feet above sea level)

Have you started blood doping, yet?

I was sitting in my office in Seattle when one of my colleagues asked me that. I didn’t know if he was serious. Admittedly, I didn’t know what the hell he was talking about. So, I deferred back to a move I learned in high school – it was my response to any offer of doping, drugs, or any other offer for a foreign substance I didn’t think was legal –

Nah, I said through a laugh, I’m good.

I was flying out to Colorado later that night on a red-eye. I landed in Denver around 1:00 in the morning. By 3:00am, I was in my rental car, heading toward the Rockies. By 5:30, I was in Estes Park, parked in the town’s public library, sleeping in the back seat of my rental (the car was about the size of a Smart Car). By 7:30am, I was driving around town to gather some last-minute supplies. By 9:00am, I was parked at the trailhead. By 10:00am, it was already 85 degrees outside, so I was hiking up the trail in the lightest clothing I brought with me: a pair of Chacos and running shorts.

The trail I was climbing led to a place called Lawn Lake, an alpine lake nestled high in the Rockies, right in the center of the Mummy Range. The trail starts off at 8,540 feet above sea level, and it winds 6.25 miles up from the trailhead to the south shore of Lawn Lake, which sits at 10,987 feet above sea level. For those of you keeping score at home, that’s an elevation gain of 2,447 vertical feet (which is a moderate - but not difficult climb – over a trail that long).

Frankly, 6.25 miles, with any amount of elevation gain, is one of the shortest entry hikes into the backcountry that I’ve had this summer. When I was in the Mojave Desert, I covered 50 miles in three days; in the Tetons, I covered more than 20 miles through the mountains in less than seven hours. My thought in keeping this entry hike shorter was that it would allow me to summit a handful of peaks over the weekend that I’d be in the Mummy Range. With the opportunity to bag five thirteeners (mountain peaks taller than 13,000 feet above sea level) in a weekend, my trip to the Rockies was more about feats of feet than it was about miles.

My ascent to Lawn Lake went smoothly. Despite climbing in my Chacos, I cruised up the trail; I took time to explore a few offshoots of the main trail and still made it to the lake in less than three hours. Shortly after I arrived, I set up camp, hopped in the lake to cool off, and I excitedly mapped out my plans for the ascents I’d make over the next two days. And while I sat on a large boulder by the lake, tracing topo lines on my map, it slowly started happening: my body began failing.

Lawn Lake, Colorado (Elevation: 10,987-11,019 feet above sea level)

Altitude Sickness is a physical condition that affects the human body as a person ascends into higher elevations, where there isn’t enough oxygen for the body to function properly. It comes in three forms, which vary in severity from mildly uncomfortable to deadly within a few hours.

The first form of altitude sickness, and the mildest, is called Acute Mountain Sickness (AMS). In addition to general heavier breathing, common symptoms often resemble that of a hangover: headache, nausea, fatigue, vomiting, and difficulty sleeping. Acute Mountain Sickness affects every person at different elevations and to different degrees, though it generally starts to become noticeable at 8,000 feet above sea level and higher, and the severity of symptoms tend to correspond directly with a person’s rate of ascent. In other words, the faster you gain elevation, the more punishing the symptoms.

The full suite of symptoms generally takes a few hours to affect most people. Though uncomfortable, AMS is rarely deadly. Once a person starts showing symptoms of AMS, the most effective treatment is to descend to a lower elevation, where the body will be able to better regulate itself. Under no circumstances, though, should a person experiencing AMS continue ascending, as AMS can evolve into one of the more life-threatening versions of altitude sickness with little warning.

While I was sitting on my boulder by the lake, tracing topo lines, my body was starting to feel the effects of a rapid ascent from sea level in Seattle to the lack of oxygen high up in the Colorado Rockies. To put things in perspective, it generally takes a person about five to seven days for their body to acclimatize to the change in elevation they experience when traveling from Seattle (518 feet above sea level) to Denver (5,280 feet above sea level). I was now sitting at an alpine lake that was more than twice as high up as the city of Denver, and I’d been in Seattle less than 18 hours ago.

Cusco, Peru (Elevation: 11,152 feet above sea level)

I’ve had altitude sickness once before. Last summer, I was in the Peruvian Andes. I’d been in the Amazon for the week leading up to my flight to Cusco, and I got food poisoning on my last day in the jungle. I was throwing up everything I tried to eat or drink. I couldn’t even keep water down. And then, I got on a plane and flew from sea level in the jungle to over 11,000 feet in Cusco. Despite having run a marathon earlier that month, I couldn’t even walk once I got out of the airport. My body was failing me. I was on a walking tour of the city, and I had to have my guide put me in a taxi back to my hotel; itl was less than five blocks away.

I fought my way up to my hotel room, which, sadistically, was located on the third floor of a building with no elevator. I was becoming disoriented, and I was losing function of basic motor skills. I probably looked like I was hammered as I stumbled up the stairs toward my room. I fumbled with my keys, forced my way into my room, and fell to the floor, covered in sweat. And then I passed out.

When I woke up, what felt like days later, I saw that it had only been fifteen minutes since I returned to my hotel. I was still laying on the floor, in a pool of my own sweat. The door to my room was still wide open. I was totally dehydrated. And then the chills started. I laid on the floor, shivering, still too weak to climb in my bed, still laying there with the door to my room wide open. I rifled through my backpack, which was on the ground next to me, trying to find a jacket to stay warm. Before I could find it, I was out again.

The next time I woke up, I didn't know how long I had been unconscious for. I was delirious. I forced myself to stand up so that I could close the door to my room, and then I climbed into my bed. I made another attempt to sip some water – thinking the migraine headache I was experiencing was the result of dehydration. But, as soon as the water hit my lips, my body revolted. I lurched into the bathroom, throwing up water and nothing, until I was crying on the floor by the toilet, alone, begging whoever could hear me to make the pain go away. This is where I’m going to die, I thought to myself, and I laid there, watching the room spin, until I faded into a nauseous, coma-like sleep.

It went on like that for eighteen hours.

Lawn Lake, Colorado (Elevation: 10,987-11,019 feet above sea level)

On my boulder by the lake, I was beginning to feel the first symptom of altitude sickness: the deep, splitting headache. I knew that dehydration came next, and that if I was overtaken by that, then my condition would deteriorate quickly. So, at 6:00pm, I finished an early dinner, drank two liters of water, and headed to bed with another full two-liter camelback hanging from my hammock like an IV. But, I couldn’t sleep.

The sun was still out. It was only 5pm back in Seattle. I was feeling nauseous. But, I was determined to try to get to sleep while I was still well hydrated, hoping to sleep through my body’s attempts to acclimatize over the next several hours. To little avail.

Over the course of the next twelve hours, I woke up more times than I could count. Checking my watch sporadically, it seemed like I never slept for more than about fifteen minutes at a time. Each time I woke, my headache was worse: it felt like someone was slowly shoving a knife deeper, and deeper, into my skull. No matter how much water I drank, I always woke up to my mouth feeling dry and coarse like sandpaper.

When I was in Peru, I couldn’t know how much of the symptoms I was experiencing were the result of my food poisoning versus how much were the result of the altitude, or how much of each condition was magnified by the presence of the other. Now, I knew what altitude sickness felt like. It was hell.

I checked my watch: it was still only 2:30am. I’d been laying in my hammock, trying to sleep, for more than eight hours. When I'd arrived at the lake, I was eyeing the five peaks of the Mummy Range, excitedly wondering how many of them I’d be able to summit during the weekend. Now, I was literally counting down the minutes until daylight so that I could get off the mountain. Fuck this place, I said to myself, and I closed my eyes for the last time that night.

The symptoms of Acute Mountain Sickness often resemble that of a hangover. During the night, when I was waking up every fifteen minutes, I would liken my symptoms to WhyDoesAnyoneDrinkAlcoholEver? In the morning, when I woke up, my condition had improved to I’llBeFineAfterAGlassOfWater.

I laid in my hammock that morning, checking to see how I felt, and assessing the extent to which I would need to re-design my trip plans in the Rockies. The way I saw it, I had two options: (1) pack up camp and head back down to the car, where I could spend the rest of the weekend exploring the park via driving and dayhiking; or, (2) keep climbing up higher, pushing towards my initial objective to summit as many peaks in the Mummy Range as I could during the course of the weekend.

I’m generally pretty pragmatic in my decision-making when I’m in the wilderness – even more when I’m traveling alone, since I don’t have the safety net of a partner to go for help if we need it. But, this decision didn’t come with a long list of pros and cons, or with strategizing around the risks and rewards of each alternative I was considering. Instead, my thinking went like this: I came here to climb mountains, damn it. And that was it. In retrospect, I wonder how many people have died with last words like those.

Those rules, simple as they are, exist for good reason: they can save your life. I mentioned earlier that there were three forms of altitude sickness, but so far, we’ve only talked about the mildest form: Acute Mountain Sickness (AMS). The other two are called High Altitude Pulmonary Oedema (HAPE) and High Altitude Cerebral Oedema (HACE).

High Altitude Pulmonary Oedema (HAPE) is a condition where a person develops a dangerous build-up of fluid in the lungs, which prevents the person’s lungs from filling up with fresh air when they breathe. Instead, each successive breath fills the person’s lungs with more and more fluid until they suffocate and die. Acute Mountain Sickness is an early sign of HAPE, which is why climbers are advised not to continue climbing if AMS symptoms are growing worse. In addition to AMS, a person experiencing HAPE will develop breathlessness even while resting, their heart rate will increase, and they’ll likely begin to cough up some of the fluid that’s filling their lungs; they may develop blue lips or feel an elevated body temperature. Once symptoms are present, the only effective treatment to save a person’s life is an immediate descent.

Similar to HAPE, High Altitude Cerebral Oedema (HACE) is a dangerous build-up of fluid, but it occurs in the brain instead of the lungs. HACE is thought to be a more severe form of AMS, where a person’s AMS symptoms (headache, fatigue, and vomiting) develop into unsteadiness, confusion, drowsiness, and ultimately a coma. People experiencing HACE experience severely impaired decision making, and may act in a seemingly bizarre or irrational way. Like with HAPE, the most effective treatment of HACE is an immediate descent.

Rocky Mountain National Park was the third most-visited national park in 2015. Yet, where I was camped out – 11,000 feet up and more than six miles from the nearest road – I hadn’t seen anyone since the morning before. Continuing my ascent would be not only a trip I would make alone, but it was taking me even further into the backcountry, to an even more remote area, where the likelihood of my seeing anyone decreased dramatically – meaning that the likelihood of me receiving help was even more remote. Up there, alone, I knew that continuing my trip would be walking a fine line between discomfort and death. I knew that my margins for something to go wrong were small, and that the corresponding consequences were potentially fatal. 

I set ground rules. I made a list of things I would look for and avoid while I was climbing up towards The Saddle between Hagues Peak and Fairchild Mountain. And then I packed my bag, and I left – heading up, when all conventional wisdom pointed me down.

The Saddle, Colorado (Elevation: 12,398 feet above sea level)

The Saddle between Hagues Peak and Fairchild Mountain is a mere 2 miles from the south end of Lawn Lake, where I camped. It was approximately 1,400 feet above where I had slept the night before – almost exactly half of the elevation gain I was looking to tackle in my ascent to Hagues Peak, the tallest mountain in the Mummy Range, and the fourth tallest peak in Rocky Mountain National Park. My plan was to hike to the Saddle, stop to assess how I was feeling, and then continue on to summit Hagues Peak, which was less than another mile away from The Saddle. I figured if I could tackle Hagues to start my day, then any other peaks in the range would be a bonus (and, I’d have the confidence of knowing they weren’t as tall as Hagues).

As I hiked around Lawn Lake, making my way toward The Saddle, I recounted the rules for my ascent:

1.     If you start coughing, the trip is over, and we’re descending immediately.

2.     If you start to feel disoriented or clumsy, the trip is over, and we’re descending immediately.

3.     If you vomit, the trip is over, and we’re descending immediately.

4.     And if you start to feel drowsy, under no circumstances do you sleep up there.

Fortunately, the hike to The Saddle starts off easy, as I was simply making my way from the south end of the lake to the north end, giving my body a chance to get used to moving again at the high altitude before I would start climbing. I left camp at 9:00am. I set a turnaround time of 2:00pm; meaning, regardless of where I was at 2:00pm, I was turning around and returning to camp. And then, the ascent began.

If I completed my first objective for the day – to summit Hagues Peak – then I would be ascending to 13,560 feet, a climb of 2,573 vertical feet. I had probably only climbed one hundred feet when my headache returned.

Golden Rule #2: If you have symptoms of altitude sickness, do not ascend any further, I remembered. Their rules, not mine. And I continued on.

I climbed another hundred feet or so. As I climbed, the severity of my headache consistently grew worse. It was as if with each step I took up the mountain, the feeling of having a knife driven into my skull was going deeper and deeper.

Golden Rule #3: If your symptoms are getting worse, descend immediately. There was no denying that my symptoms were slowly getting worse with each step I took. But still, I felt like I had things under control. I’ve made my own rules, I told myself. I’m not coughing, I don’t feel clumsy, I don’t feel nausea… we’re fine. Just take your time and keep breathing, I told myself, knowing that I was potentially flirting with a deadly condition, yet refusing to believe it would kill me.

When I’ve got a fully-loaded pack on, I typically travel at a speed of 3-4 miles per hour. That afternoon, it took me three and a half hours to reach the Saddle: a mere two miles (with 1,411 feet of elevation gain) from where I started my day. When I reached the ridge line that was The Saddle, I had mixed emotions: on the one hand, I was elated to have reached the halfway point to Hagues Peak in relatively sound condition; on the other hand, it had taken me three and a half hours to climb a just 1,411 feet. The rest of the way up would be no only steeper, but over more difficult terrain.

I walked to the far north end of The Saddle to take in the view over the back side of the ridge toward Rowe Peak and the Rowe Glacier. I found this beautiful field of wildflowers and sat down to take in the view. And then, feeling totally spent, I broke one of my own rules: I fell asleep.

Hagues Peak, Colorado (Elevation: 13,560 feet above sea level)

I woke up half an hour later, an outline of where my body had been pressed into the patch of wildflowers on the hillside. It was still before 1:00pm. I feel great, I thought to myself, a little sleepy, but great. I can still make a push for the summit. With when I was leaving my napping spot, I’d have about two hours to climb 1,162 vertical feet and about 0.7 miles.

My ascent of Hagues Peak was one of the only times in my life where I’ve truly had an out-of-body experience – the type of thing where your mind is fully functioning, fully aware of the situation that’s unfolding, and yet, your body is physically unable to cooperate with what your mind is willing it to do. It was like I was watching myself.

Now, instead of stopping every hundred feet of elevation gain, it felt like I was completely depleted every 25 feet that I climbed. Alright, let’s climb this fucking thing, I ‘d say to myself, mentally invigorated and excited about the challenge of the task at hand. And, yet, my lungs and my legs were failing me. I couldn't move continuously for more than about 60 seconds at a time. I could literally hear my heart beating out of my chest. It was pounding harder than I’ve ever felt it before.

A person experiencing HAPE will likely experience breathlessness, an elevated heart rate, and… I was going down. I was fading. One minute I was climbing up a boulder field, the next I was searching for a place to lay down between the rocks. I need to get my heart rate down… I told myself. I just need a few minutes to…

And I was down. I was passed out in a boulder field on one of the tallest mountains in one of the most remote places in Rocky Mountain National Park. Short of a search and rescue team combing the mountain, there was no shot of me receiving any sort of outside help.

I woke up an hour later. I feel good, I told myself. I could see the top. I’d now violated one of my own rules, twice now, but I could see the top. I’m going for it. And, I kept climbing.

And then 2:00pm hit, my turnaround time. If I had a fifth rule, it was that I was going down the mountain, no matter what, at 2:00pm. The sun doesn’t set up here until about 9:00. It only took me five hours to get to this point, including two “naps.” I’ve got more than enough daylight if I push my turnaround time out until 4:00pm to still get home. My decision-making was shitty, but my argument skills were still decent. I took that as a sign of mental capacity, and I continued up the mountain.

I probably stopped fifteen times on my way up Hagues Peak, but only two of them were under my own will. The first was about halfway up the mountain. If I have to stop here, I’m fine with it. I’m at peace with it. My body is exhausted. I’ve fallen asleep twice on my way to get here. The view up top isn’t going to be significantly different from what I’m seeing right now. There’s no prize waiting for me up top… just be at peace with the damn thing and move on.

But there was this over voice I heard, too. It was quieter – softer – and it reminded me of a simple statistic in my hiking and climbing career: you’ve never not finished before, it said. I weighed that fact, that voice, against the other one in my head. Just be at peace with the damn thing. And I tried to; but, I couldn’t. I looked up at the summit, and I started climbing again.

A guy by the name of Alex Honnold is arguably one of the greatest climbers in the history of the sport. Period. He’s famous for a style of climbing called “free soloing,” which essentially means that he’s climbing both without a partner and without ropes (here’s a sample of the type of stuff he does). In response to the climbs that Honnold attempts, he’s often asked about whether he must be crazy to take on the sort of risks he does, or whether he’s missing the gene responsible for a person to experience fear.

In response to some of those questions on risk and fear and courage, Honnold introduces an interesting view on the notion of risk. Honnold says, “I feel like people need to differentiate between risk and consequence. The risk of falling off something is sort of determined only by how hard the climbing is, how solid the climber is, that’s kind of something that only the climber can really know. But, the consequences of falling off something, you know, can be pretty obvious just by looking at a photograph.” In other words, Honnold separates the risk, or the likelihood of falling, from the consequences of falling. In my experience in the wilderness, I’ve always viewed situations of high consequence in the same way: preparing for potentially dangerous situations by asking questions not only about the consequences of things going awry, but by the likelihood of them actually happening. Put differently: you and I may both be climbing up the side of the same mountain, a situation with identical consequences were either of us to fall, but we may be taking entirely different levels of risk based on our differences in skill.

As a general rule of thumb, when I’ve confronted the limitations of my comfort zone throughout my experiences in the wilderness, it is only when both the riskiness of my actions and the consequences of my actions are both higher than I’m comfortable with that I forego a climb or a route or an activity. When I stopped for the second time on Hagues Peak, about a hundred feet shy of the summit, it was because the combination of risk and consequence were higher than what made sense. I was put in a position where I’d have to scramble up a set of unstable rocks, with my physical condition somewhere between AMS and early-onset HACE, where a clumsy move or a loose rock would have sent me down a few hundred feet onto the Rowe Glacier down below (to my death).

So, I stopped there, about one hundred feet below the summit. I took in the view. I reflected on how far I’d come; how far I’d climbed. I reflected on the internal dialogue I’d kept with myself. I wondered whether my AMS was progressing into HACE, and whether I’d be able to make it down safely. I reflected on the fact that this was the first route I’d ever attempted and not finished. In some ways, I felt like failing was a sign of development in my decision-making; it showed that I was mature enough to let go of something when the time was right.

Seattle, Washington (Elevation: 518 feet above sea level)

Until writing this, I haven’t told anyone the severity of what things were like up there. Some stories you keep to yourself to protect the people that love you, that worry about you. Some stories you keep to yourself to avoid looking like you made poor decisions, or that you aren’t perfect. But, this was a story I felt like I had to share: not because I felt like what I did was admirable, but rather, because I felt like it was the opposite of that. I wanted people to see that there’s a really, really fine line between safe and unsafe out there; I want people who read this to understand that impaired decision making and altitude sickness are both real things; that my story could have easily ended with me, passed out, dead, on the side of a mountain in Colorado because of my ego.

But, at the same time, I wanted people to see the ambiguity of what a person encounters in the wilderness: that the answer to stop or go isn’t usually obvious; that you won’t usually know whether you have AMS or HACE; that you’ll ultimately have to make your own decisions about how risky something is and whether you should keep going.

The only real rules in the wilderness are the ones you set for yourself, and they’re loaded with grey area. I think there’s real beauty in that. I think that's how life really is.