The monotonous beeps from Brian’s watch broke the silence in the two-person tent, where three of us had crammed for a night of sleep periodically disturbed by the sound of the wind.

Crawling clumsily over the pile of sleeping bags and gear, I launched myself out of the vestibule. The menacing clouds that had enshrouded the Stone Sentinel at sunset were gone, revealing a rocky, imposing silhouette against the navy blue predawn sky.

After a meager breakfast of lukewarm cocoa, I put on almost every layer I had and shoved a Nalgene of warm water into my pack. The bitter cold of the alpine morning stung my fingers as I frantically laced up my boots. Clusters of headlamps dotted the mountain above us as we departed in darkness.

An hour later, the sky began to lighten. I’m sure the sunrise was spectacular, but I wasn’t paying attention. All of my mental energy was focused on breathing, trying to warm my fingers and toes, and keeping my head in the game as I continued toward the summit of the highest mountain in South America — Aconcagua.

At some point during the maturation of my climbing infatuation, which began in 2007 when I struggled up La Plata Peak outside Buena Vista, I set a goal of climbing one of the seven summits — the highest peak on each continent — before age 25. In October 2012, with less than a year left to make that happen, I figured it was time. I met up with two partners — Brian Carpenter and Nick Mentzer — via 14ers.com and left for Mendoza, Argentina on Christmas Eve.

After dropping 4,700 Argentine pesos (about $750) for permits and another 2,000 pesos for mules to carry food and gear to Plaza Argentina — the base camp for the routes on the east side of Aconcagua — and transportation to the trailhead, we began the three-day trek up the Vacas Valley.

Plaza Argentina sits amid hills of talus below the rocky slopes and snowfields of Ameghino. Though not as large or luxurious as Plaza de Mulas — the base camp for the normal route — it’s equipped with medical huts, latrines and a helicopter landing pad.

For the right price, climbers can get cold beer, hamburgers, showers and Internet access. Climbers are required to check in at the ranger station and undergo a basic medical exam. The doctor checks your heart rate, respiration rate, blood pressure and blood oxygen-saturation levels. We all passed with flying colors.

The first morning at Plaza Argentina, we learned of the deaths of two climbers on the Polish Glacier route. Later that day, we encountered a team of guides recovering one of the bodies from high on the mountain. It was a sobering reminder that while Aconcagua is a nontechnical peak, the altitude and weather are very real and potentially deadly.

From base camp, we ascended the Guanacos Valley route to three camps on the mountain — Camp 1 (16,300 feet), Camp Guanacos (18,900 feet) and Camp Colera (19,600 feet). Each day we did double carries — bringing a load of extra gear, food and fuel to a higher camp before returning to the previous camp for another night — to help acclimatize and conserve energy.

Finally, the day arrived. Ten days of living in a tent, drinking silty water and eating Mountain House, oatmeal and Mojo bars, and shouldering a pack every morning to seek out a progressively colder and more oxygen-depleted place had led to this. Months of planning and training had been devoted to a journey that took me farther from home than I’d ever been.

Now, it came down to eight hours of pushing through the thin, frigid air, up the slopes of reddish-brown scree to the 22,841-foot summit.

The route is straightforward, but Aconcagua is an entirely different mountain than the ones I’d climbed in the United States. On almost any peak in Colorado, altitude might be a minor factor, but it doesn’t usually decide the outcome. On Aconcagua, altitude is everything.

At 12,000 feet, you get winded a bit easier than usual. At 22,000 feet, you literally stop after every five or six steps and take a couple of breaths. At lower elevations, you can mitigate the effect of subfreezing temperatures by hiking a little faster to generate more body heat. This is not an option at high altitude. A weekend hike up a fourteener might be impeded by a headache or mild nausea. On Aconcagua, the altitude can kill you.

Climbers are evacuated from base camp via helicopter almost every day after developing high altitude pulmonary edema or high altitude cerebral edema, and these afflictions claim a few lives every year.

The weather window on our summit day was as good as anyone could have hoped. After the first couple of hours, the Pacific Ocean winds that assault the westerly aspects of the mountain ceased.

At about 1:30 p.m., we reached the summit. Under the warmth of the sun, I stared out across the vast landscape of the snow-capped Andes under the clear, blue sky. To the west, the south face — a 9,000-foot wall of snow cut by intermittent rock bands — stood as a testament to Aconcagua’s prominence over the surrounding peaks.

After doing a summit ritual that included photos, rewarding my efforts with cinnamon cookies and doing a brief performance of the “Gangnam Style” dance, we headed down to Camp Colera.

The next day, we returned to Plaza Argentina, where we celebrated our success with burgers and beer. Then we shared a 50-peso bottle of whiskey, which I’d picked up in a grocery store in Mendoza and stashed at base camp, with the team of two Scottish climbers and an Australian guide that we’d befriended on the way to the top.

I watched the altocumulus clouds fade to orange and then to pink as I finished packing my gear for the 30-mile trek back to the trailhead the following day. The hike out was exhausting, but the hot showers, cold beer, good food and warm beds that awaited us at the hostel in Los Penitentes — Refugio Cerro Aconcagua — were more than worth it.

Aconcagua is certainly a formidable challenge — and to the adventure-minded individual, there are few things more rewarding than pushing one’s own limits. Whether that means tackling Pikes Peak, Mount Rainier or Cerro Aconcagua, the feeling of achievement from standing on a summit is one of the best things a human can experience.

Photo by AMY MCMILLIN, SPECIAL TO THE GAZETTE

Photo by AMY MCMILLIN, SPECIAL TO THE GAZETTE

Photo by AMY MCMILLIN, SPECIAL TO THE GAZETTE