Acknowledged as America’s premier Himalayan mountaineer, Ed is the climbing leader for the Return To Everest expedition. Back for the tenth time, and going for his seventh summit (again without bottled oxygen), Ed will establish key locations, provide an overview of Everest, and outline the objective dangers the expedition entails for his team.

Co-owner of Rainier Mountaineering, Inc. (RMI), Peter, along with Eddie Bauer CEO Neil Fiske, is the one who brought this all-star team of mountain guides together. He’s returning to Everest for the third time, and going for his first summit. Peter is walking in the footsteps of family legend: On May 1, 1963, his uncle Jim became the first American to reach Everest’s summit. In 1984, Peter’s dad, Lou, led the first American team to summit via the North Face.

Recognized as America’s leading Himalayan guide, Dave has reached the summit of Everest more times (10) than any non-Sherpa in history. This year, as he attempts his eleventh summit, he’ll be guiding a young client trying for her first. Many of his posts will point out essential strategies for climbing the world’s highest peak.

A senior RMI mountain guide, Melissa is attempting her second Everest summit in as many years. In 2008, she reached the top as part of EVEREST TEAM INSPI(RED) to help raise awareness for the organization (RED) and its work for people in Africa suffering from HIV/AIDS. This year, as a member of the First Ascent Guide Team, she’s going to “meet the mountain on its own terms” and attempt to summit without bottled oxygen.

Another RMI mountain guide, Seth is making his first trip to the Himalaya. He’ll be assisting Dave guide their young client in her attempt to summit. While new to Everest, Seth has guided on Rainier, Denali and Kilimanjaro; and he has multiple first ski descents to his credit. He also works as a ski patroller at the Crystal Mountain Ski Area in Washington State.

When Hillary and Tenzing Norgay summited in 1953, and when Jim Whittaker and Nawang Gombu summited in 1963, the closest the expeditions could get to Base Camp with motored transportation was Kathmandu, Nepal. That’s 180 miles from the mountain. So mountaineers had to assemble their gear in Kathmandu and walk to Base Camp—a trek that typically took more than a month. Today, climbers fly from Kathmandu to Lukla—a 30 to 50 minute flight that reduces the walk to Base Camp to about 10 days.

But this 10-day trek remains an important preparation for the actual climb. On the trail, mountaineers go from an elevation of about 9,000 feet in Lukla to well over 17,000 feet at Everest Base Camp. There are planned rest stops along the way to aid in acclimatization. In fact, Ed Viesturs calls these rest days “acclimatization days,” and uses them to do additional climbing in order to build his endurance and increase the oxygen-carrying red blood cells in his body. He knows he’ll need those on the mountain. Similarly, when he guides on Everest, Dave Hahn uses the trek into Base Camp as a training ground for his clients. It’s here that he teaches pacing—too fast wears you out, which causes problems higher up; too slow also increases fatigue and compromises the chances of climbing successfully at higher levels. In fact, Dave says that, “Getting the walk to Namche [11,296 feet] right is crucial for climbing Mount Everest.”

While not Yosemite in the summer, Everest Base Camp is a relatively crowded place during the climbing season. As many as 300 people—climbers, Sherpa, medical and support staff—gather at Base Camp in the spring. This is the logistical hub of expedition operations. Teams plan their climbing strategies here, continue their acclimatization, begin ferrying loads through the Khumbu Icefall to the higher camps, and return for rest and medical attention, as needed. Base Camp is also their connection to the outside world.

Just above Base Camp is one of the most dangerous sections of the mountain. The Khumbu Icefall is a jumble of massive ice blocks, called seracs, and suddenly shifting crevasses. Because the Khumbu Glacier advances as much as three to four feet each day, the Icefall is in constant flux. Crevasses open and seracs—some of them several stories high—collapse without warning. Compounding the risk is the fact that most climbers have to traverse the Icefall multiple times—both to ferry loads to the higher camps and for essential acclimatization. To minimize the danger, they usually go through the Icefall early in the morning before the heat of the day warms the ice, making it unstable. More people have died in the Khumbu Icefall than on any other part of the mountain.

Just beyond the Khumbu Icefall is Camp I, at 19,900 feet. From Camp I, climbers cross the Western Cwm (pronounced “koom”) to Camp II, at 21,300 feet. The Cwm is a bowl-shaped valley protected from wind but exposed to intense sunlight. One of its greatest challenges is the equally intense heat, even at this elevation. Once the climbers leave Camp II, they must negotiate the Lhotse Face. Lhotse is the neighboring peak to Everest, and is itself the world’s fourth highest peak at 27,940 feet. Fixed ropes are required to cross the sheer wall of ice of the Face to reach Camp III, at 24,500 feet. Ropes are also required to climb to the highest camp, Camp IV, at 26,000 feet. Here, climbers are sleeping in the so called “death zone.”

The progress up the mountain from Base Camp to Camp IV and the summit is not continuous and linear. Most climbers go up and down between camps many times. Teams within the expedition may leapfrog each other as they ferry loads to supply the higher camps and then retreat to rest (“climb high, sleep low”). Because even the strongest climbers are limited in how long they can stay in the death zone above 26,000 feet, the timing of when a summit push is made and who is ready to make it are critical decisions for the expedition leaders and the individual climbers to make.

On the day of the summit push, climbers are ideally on the trail above Camp IV by midnight. They need to ascend the last 3,000 vertical feet by 1:00 pm in order to have time to safely descend again. Many of the fatalities on Everest and other big mountains have happened because climbers, close to the summit, have pushed to the top well past the established turnaround time. Even if they reach the summit, they may expend all their physical and mental reserves. Ed Viesturs, renowned for his conservative approach to climbing as well as for his remarkable accomplishments, maintains that, “To reach the summit is optional; to get back down is mandatory.” More than once, Ed has turned back a few hundred feet short of a summit because time or conditions dictated safety and caution over reaching a goal. While the record for the longest time spent on the summit of Everest is 21 hours by Babu Chiri Sherpa (without bottled oxygen!), most climbers spend 30-90 minutes on top before they begin their descent.

In geological terms, Mt. Everest and the Himalaya are relatively young—only about 60 million years. Still, that’s a fairly long time for the highest point in the world to remain hidden and unknown to most of the world’s population. In fact, it wasn’t until the middle of the 19th century that Everest’s existence and prominence entered the consciousness of Western culture.

At the time, Kangchenjunga was considered the tallest mountain. Part of the problem was that the borders of both Tibet and Nepal were closed to outsiders. So when British surveyors began measuring the Himalaya, they had to do so from more than 100 miles away. It wasn’t until 1852 that the highest point in the world was clearly identified.

Once it became official that Everest is the highest peak in the world, climbers began dreaming of testing themselves on it. But it wasn’t until 1921, when Tibet opened its borders to outsiders, that European mountaineers could get close. That year, the British sent a reconnaissance team to explore the North Face. They returned in 1922 to make an attempt at the first ascent. This expedition reached 27,000 feet (a new record) before being rebuffed by storms. Seven Sherpas were killed in an avalanche on that climb, Everest’s first recorded climbing deaths.

In 1923, George Mallory, who had been on both of the earlier expeditions, went on a lecture tour in the U.S. In answer to the question of why he climbed Everest he replied, “Because it’s there.” The following year, Mallory and Andrew Irvine disappeared high on the mountain, the first European casualties. In 1950, China closed the borders of Tibet, shutting off access to the North Face route. But Nepal opened its borders, giving climbers access to the Khumbu Valley and the southern approach to the mountain. On May 29, 1953, Edmund Hillary and Tenzing Norgay Sherpa reached the summit via the South Col.

The vagaries of Everest’s existence are mirrored by the history of its name. When rumors of its presence began to circulate among the British surveyors, it was first referred to simply as “Peak B.” Then a numeric system was employed and it became “Peak XV.” It was generally the practice of the British Surveyor General of India to follow local custom in naming mountains. But because Tibet and Nepal were closed, the Surveyor General, Andrew Waugh, claimed that no local name could be found. Without that, he named it for his predecessor, Sir George Everest. Apparently, Sir George was not in favor of the name, but it stuck. By the time Tibet opened its borders in 1921 and Nepal followed in 1949, their local names for the great mountain—Chomolungma and Sagarmatha, respectively—had been supplanted. Everest remains the only major Himalayan peak with a European name.

The famous Sherpa of Nepal’s Solu-Khumbu region are actually Tibetan. The word Sherpa means “people of the east.” They emigrated from eastern Tibet into the Khumbu Valley near Everest about 500 years ago. Renowned for their remarkable strength and endurance at high altitude, the Sherpa have gained worldwide recognition over the last 50 years as porters and guides for most of the expeditions in the Himalaya. One quarter of the successful Everest ascents and one third of the deaths on the mountain have been Sherpas. Because of the mountainous terrain and lack of roads in the Khumbu, there is relatively little use of wheeled transportation. Even today, most travel is by foot; most transport is by loads carried on the back.

Ninety percent of Sherpas are Buddhist. The influence of their beliefs can be seen in everything from the “mani stones” (rocks carved with religious mantras) and multi-colored prayer flags along the trails to their well-documented compassion and gentle nature during the trials of a long expedition. It’s also evidenced in the structure of their names. “Ang,” a common Sherpa name, is an endearment meaning “beloved.” Sherpa children receive multiple names, including one for the day on which they’re born. It’s believed that whenever the child’s name is spoken, this invokes the protective power of that day’s deity. Many children also receive a “virtue name” that translates to such traits as wisdom, courage, beauty and long life.

While Everest is not considered as technically difficult as some of the world’s other major peaks, it still offers serious challenges. Chief among these is its extraordinary elevation. At 29,035 feet, it’s thought to be very close to the limit of what humans can survive, even with supplemental oxygen. The biochemical changes that the body goes through at this elevation—reduced oxygen in the blood leading to a reduction in mental acuity, manual dexterity, appetite, sleep and resistance to cold—require careful planning, disciplined training and well-orchestrated timing in order to acclimatize to the thin air, especially in the “death zone” above 26,000 feet.

This need to acclimatize dictates much of the strategy in climbing Everest, from the pace of the trek into Base Camp, to the amount of food eaten at the lower elevations, to the use of multiple camps on the mountain. The basic philosophy is to “climb high, sleep low.” That is, to push the camps and set the fixed ropes as high as possible each climbing day, but then to retreat to lower camps to sleep whenever possible. This helps to improve sleep and minimize the effects of the thin air. The added time for acclimatization and the practice of going up and down multiple times between camps (along with waiting for climbable weather) are the primary reasons why an Everest expedition generally takes about two-and-a-half months to complete.

As with all alpine regions, the Himalaya are a fragile ecosystem. The explosion of mountaineers, trekkers and general tourists that have come to the Khumbu since the first ascent of Everest in 1953 has been a mixed blessing. It has generated a significant lift to the local economy. But it has exacted a high price on the environment. Since wood is a primary source of fuel, deforestation has increased dramatically, which speeds soil erosion. The tons of litter left by expeditions around Everest’s camps have been a source of controversy for many years. Photos of thousands of discarded oxygen bottles on the mountain have been widely distributed. But castoff batteries and fuel canisters, as well as human waste, are more dangerous to the environment.

In 1976, Nepal created the Sagarmatha National Park that includes Everest and the surrounding area. In 1979, the region was named a Natural World Heritage Site. Flora and fauna in the Park are now protected, and collecting firewood is prohibited. In addition to climbing fees, the government of Nepal requires expeditions to pay a $4,000 deposit that is only returned if the climbers pack out what they packed in.

In 1990, Jim Whittaker led an International Peace Climb that removed some of the accumulated trash. In 1998, the Everest Environmental Expedition packed out another 1.2 tons of trash. Other environmental expeditions continue the effort. The late Sir Edmund Hillary recommended that the government of Nepal place a temporary moratorium on climbing permits so that further cleanup could be organized and the ecosystem could better recover from the heavy use. But the economics of the region have made this an unpopular—and untried—option.