In 2003, Burke climbed the Aconcagua in Argentina's Andes Mountain Range. In 2004, he reached the apex of Mount Kilimanjaro in Africa. A year later came Mount Elbrus in Russia. After that it was Vinson Massif in Antarctica, Mount Kosciuszko in Australia and Indonesia's Carstensz Pyramid.

Burke's wife, Sharon, and their children and grandchildren, were supportive of, if not particularly thrilled about, his climbing hobby.

Then, as he approached 65, Burke embarked on something truly big.

In 2007, he made it to the southeast ridge of Mount Everest, about 300 vertical feet from the summit. But, abandoned by his Sherpa, a mentally and physically exhausted Burke had to make a choice: Should he continue up, alone, to complete the ascent? Or should he be prudent and start down the mountain, failing to reach his goal? It was, literally, a life or death decision.

He chose to head home. Life was too precious; his family was waiting.

"I was disappointed," Burke says. "I had been on the mountain for eight weeks."

Still, there was no doubt he'd try again.

"Once I came down, I felt good. I knew that the mountain would be there the next year, and the year after that."

In 2008, Burke tried again to summit Everest, but a pulmonary edema — a lung malady often caused by breathing at high altitude — prevented him from even reaching base camp. A helicopter flew Burke out of the mountains, momentarily ending his dream.

Then, in late March of this year, Burke again left home for Everest.

Along with his new Sherpa, Mingma, Burke trekked up and down the mountain for eight weeks. They dealt with storms, witnessed an avalanche that killed another Sherpa, and sometimes camped for days, alone in a tent, until it was safe to move on.

Unlike his previous stints on the mountain, Burke didn't feel altitude sickness or out of breath. Training he had done at home — gym workouts three or four times a week, plus climbing local mountains and biking with his grandson Oliver, who has Angelman Syndrome — prepped him for the journey.

When it was time for a final drive to the summit, Burke and Mingma knew there was a cyclone in the Bay of Bengal, something that would soon turn the weather on Everest into something lethal. Still, he felt confident.

On May 23 about 8:30 a.m., Burke reached the summit, dropped to his knees and thanked God. The wind was so intense that he couldn't take off his oxygen mask or goggles.

But he could unfurl a small American flag, and a second flag he'd made in honor of a foundation representing Oliver's disability, a genetic disorder that can involve a sunny disposition but also problems with coordination and communication. Burke took photos and, after 30 minutes, began the dangerous trek back.

Life on flat ground isn't boring for Burke.