By Shawn Scully

photos courtesy of shawn scully According to Aztec myth Popocatepetl, above, is a warrior god holding a funeral torch for his dead beloved.

In January, my friend Morgan and I flew into Mexico City with the goal of tackling two of the tallest mountains in North America: 17,342-foot Iztaccihuatl and 18,405-foot Pico de Orizaba.

Despite our disappointment that some of the mountain glaciers had receded, and an unexpected illness, the adventure proved to be invigorating.

Mexico is home to some of the tallest mountains in the Northern Hemisphere, with Orizaba a close rival to Denali, the tallest mountain in North America at 20,322 feet.

Orizaba’s glaciers, however, have significantly receded during the last decade and seem like mere snowfields compared to Alaska’s Denali, which is heavily cloaked in massive ice floes.

We spent our first two nights at Hotel Isabel in the historic district of Mexico City, sightseeing, enjoying numerous cafes con leche and purchasing supplies to head into the mountains.

At 7,349 feet, Mexico City allowed us to begin acclimatizing. From my hotel window, I could see an ornate 19th century cathedral and the packed streets of the metropolis.

The capital’s 18 million residents make it one of the most populous cities in the world. An easy stroll brought us to the Presidential Palace, home to some of Diego Rivera’s most famous murals, and the Zocolo, a bustling central square with vendors and street performers.

Adjacent to the square stand the Aztec pyramids, where the city was born. According to myth, the Aztecs decided to build their massive city in the spot where they saw an auspicious omen - an eagle with a snake in its mouth standing on a cactus.

The next day we traveled 30 miles outside of the city to climb Iztaccihuatl, “the white woman.” Iztaccihuatl is separated from the smoking 17,887-foot active volcano Popocatepetl by Paso de Cortes, or Cortez Pass.

Legend has it that Popocatepetl, a mighty warrior, and Iztaccihuatl were lovers. When Cortes invaded, Popocatepetl went off to fight his army. Out of grief Iztaccihuatl killed herself.

When Popocatepetl returned to find her dead, he created two mountains. He laid her on one and, standing, holding her funeral torch, he became the other.

When glaciated, Iztaccihuatl looked like the profile of a reclining white woman; but over the last two decades her glaciers have nearly all melted.

We spent an excruciating night in a mountain hut at 14,000 feet elevation, feeling sick from the altitude, but by the next morning we were feeling better and went for an acclimatization hike.

The following day we set out for another hut, elevation 15,000. Because the snows had melted and the hut had no well, we had to carry our water - about 2.5 gallons per person - up with us. The hike was dusty and windy, like traversing a desert in a sandstorm.

After another restless night, during which the sand blew through the cracks in the walls, coating us with a fine dust, we rose for a mountaineer’s start, departing for the summit at 2 a.m.

The climb was a long, exposed ridge traverse. When we were nearly upon the ridge, we were blasted by strong winds. In spite of our adventuresome attitude, we decided the idea of climbing hours on an exposed ridge while being blasted with 50-60 mph gusts of wind was unappealing and dangerous. We hunkered down behind some rocks that acted as a windbreak.

By dawn it was clear the winds would not abate, so we began our descent. The view was magnificent: Looking down to our right we could see Mexico City, somewhat smog-obscured in the distance, while to the left we were presented with its neighboring city, Puebla.

That afternoon we hitched a ride from a professional mountain guide to Cholula. Just outside of Puebla and home to the widest pyramid in the world, Cholula seemed the perfect place to relax.

Morgan and I were pretty sick with chest colds brought on by the strain from the altitude and the dust and cold of the mountain. Taking a couple of days to recuperate before climbing nearby Orizaba was just what we needed.

After a night in Cholula and one in Puebla, the birthplace of molé (a sauce made from chilies and chocolate), we took a bus to Tlachichuca, the major jumping-off point for ascending Mexico’s tallest mountain, Pico de Orizaba.

In Tlachichuca we gathered supplies and hired a driver to take us to the base camp of Orizaba. We rode up rugged roads, passing hundreds of grazing sheep, as well as some donkeys and goats.

Like Iztaccihuatl, Orizaba was dry and dusty, but its massive glaciers still remain, beginning 2,000 feet below its summit.

The trick to getting used to altitude is to go high but sleep low; but even when you don’t feel sick at a high altitude, you don’t feel good.

Our driver dropped us off at a hut 14,000 feet up the mountain. We spent one day acclimatizing by hiking up to 17,000 feet and then back down to the hut. By this time I had started to feel better.

We began our trudge up the mountain the next morning, again at 2 a.m. Halfway to the summit, I was feeling even better, but Morgan had started to feel sick. We kept on, though.

At the toe of the glacier we put on our crampons, pulled out our ice axes and stepped onto the icy snow. For hours, it seemed that no matter how many steps we took we weren’t getting any closer to the summit.

It was a climb of determination - brutal and tiring. It slowly became apparent that Morgan wasn’t merely tired; he had altitude sickness. For a while, I had been thinking that he was just quiet because he, a novice at mountaineering, had realized how hard the day would actually be. High-altitude mountaineering is exciting, challenging and spectacular, but rarely fun.

About 30 minutes from the summit we stopped for a snack, which did not, as I had hoped, perk Morgan up. He was sluggish and barely aware of what was going on around him. I realized that although we were nearly to our goal, the decision to descend had already been made for us. This was my second attempt to summit Orizaba, but I knew Morgan needed to get down from the mountain before he stumbled and went sliding down the steep slope.

We turned our backs and headed down, each step bringing us out of the thin, cold air and away from the pull of Orizaba’s summit.

Shawn Scully is a materials engineer at Stanford University. He resides in Mountain View.