"I'm hoping that it will show other people in my situation that there is hope," David Clark tells PEOPLE

By Tiare Dunlap
Updated April 08, 2016 10:40 AM
Credit: Courtesy David Clark

“Every morning when I wake up, the first thing that crosses my mind is, ‘You have terminal cancer,’ ” David Clark tells PEOPLE. “The second is, ‘What are you going to do with this day?’ ”

Despite his stage IV lung cancer diagnosis, the 51-year-old father of three has come up with an inspiring answer to that question. Together with his 24-year-old son, Matthew, Clark is on a mission to climb all 46 high peaks of New York’s Adirondack mountain range. It’s a personal project with a very public message.

“I’m hoping that it will show other people in my situation that there is hope,” he explains. “The diagnosis of a non-curable disease does not mean your life is over.”

The New Egypt, New Jersey, man believes his life is far from over, but that inspiring mindset is far from how he felt when he was diagnosed in January 2015. His lung cancer diagnosis ((non-small cell adenocarcinoma stage IV) came after Clark had a hard time regaining weight after an arduous ice-climbing trip.

During what Clark thought would be a routine doctor’s visit, a CT scan revealed a golf-ball sized tumor on his spine. A series of tests found the tumor’s source to be an advanced case of terminal lung cancer.

“Hearing, ‘You have cancer,’ for the first time and then hearing, ‘You have non-curable cancer,’ there’s no other word for that but devastating,” Clark says. “I’ve always dreamed about growing old with my wife and sitting on the front porch with her and our children and grandchildren and to receive news that more than likely that won’t happen for me, that’s devastating. I cried for the first three days.”

That mourning period was followed by radiation, a surgery to remove the tumor and a new regimen of chemotherapy every three weeks. Despite this aggressive treatment, doctors told Clark he had an 80 percent chance of dying within a year and a 99 percent chance of dying within five years. It’s a grim prognosis that Clark has accepted, but that doesn t mean he has given up on the life he has left.

“I decided very early on that I was not going to allow cancer to deprive me of the things that I love,” he explains. “There might come a time when I may not be able to do all the things that I love, but today is not that day. ”

So, Clark has decided to keep doing one activity that has brought him joy for the past 18 years – climbing mountains with his son. To date, the pair has summited three peaks above 4,000 feet in New York’s Adirondack mountain range.

While the effects of his disease and treatment have made climbing more difficult, Clark says he gets strength from his time in nature. “When you’re outdoors, I think you appreciate the beauty of the world more – and for me, that’s very powerful and it’s rejuvenating,” he says.

No matter how difficult climbing becomes, Clark says he’ll remain driven by his desire to raise awareness about lung cancer, which is among the least-researched forms of the disease. Clark, who was a smoker, believes the lack of research funds stems from lung cancer’s stigma as a disease that it only affects smokers.

“Smoking will more than likely be the cause of my death, and I quit years ago, but I still own that,” he says. “However, we cannot – nor should we – determine treatment and research based on human behaviors.”

“The survival rate for all cancers has increased in the past 15 years except for lung cancer. Part of why I’m climbing these mountains is to say to everyone who will listen that we need to look at this disease and know that there are humans behind the statistics,” he continues.

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Clark will keep climbing and keep trying to find beauty in each day for as long as he is able.

“I’ve found beauty in the mountains and I’ve found more beauty, generosity and empathy in people than I ever thought possible over the past 14 months,” he says. “In many ways, cancer has opened my eyes to how beautiful our world truly is.”