Jenkins loves trees so much, he even names them.
"This is Nimrod," said Jenkins pointing to a tree. "Notice Nimrod has these big beefy branches. He looks like he's lifting weights... He's a strong guy. He loves climbers."
He loves climbing trees so much that, in 1983, he founded Tree Climbers International. Since then, he has become a pied piper for the growing sport of tree climbing.
"This is Diana," said Jenkins pointing to another tree. "This is Nimrod's mate. And notice she has long slender branches. She's harder to climb than Nimrod."
Nimrod and Diana are living classrooms at the tree climbing school Jenkins runs two Sundays a month in Atlanta.
On the day that CBS News Sunday Morning Correspondent Rita Braver visited Jenkins' school, he was prepping kids for their climbs. He tells her that everyone can climb, whether they've done it before or not.
Jenkins is an arborist by trade. His job is taking care of trees. He modified all his professional techniques and gear for recreational climbing.
He figures he has taught thousands of first-time tree climbers. He even got Braver to try it — giving a whole new meaning to "interview on the fly."
Jenkins says it feels great to be up on the tree. "I don't want to go down," he said.
Neither do Carolyn Tews and her daughter, Zoe. "The height, the tree, the tree hugging me, the wind in my face … it's great," explained Carolyn.
"The man I love and the man I live with is the founder of this sport," said Patty Schwartzman, Jenkins' girlfriend. "His heart is in it and if he wants to do it, I want to do it."
You probably won't be amazed to learn that Schwartzman has become a dedicated tree climber, until you learned a bit more about her. "I had polio when I was 2 years old," said Schwartzman. "I'm 50 years old now. So I'm on crutches. I climb with one leg … my right hip is fused, so my sense of balance is off. And so I'm using my arms more than most people would be, doing this sport."
And now she is training for the climb of her life — a tree-climbing adventure that's daunting even to pros like Jenkins. The couple is headed out to an old growth forest in Washington state. Their aim is to climb a 1,000-year-old, 200-foot Sitka spruce and spend the night in its branches.
"I mean, this is a big tree," said Jenkins. "And she's been training for two months. And, it's hard on her. This ain't no walk in the park."
Schwartzman predicted, "I think the reaction from a lot of people on first sight is gonna be, 'These people who are climbing are out of their minds.'"
"Not necessarily, not necessarily," countered Jenkins. "When you're there for more than just one hour, when you spend the night in a tree, you just develop a different relationship to trees. Your whole concept of trees has totally altered in one day. It's amazing."
Schwartzman said her disability has never swayed her from wanting to climb. "Because post-polio's are unstoppable. You know, if we make up our mind to do something, we're gonna do it," said Schwartzman.
"She's a tough old bird," said Jenkins.
Schwartzman is serious about her climb. She's turned it into a charity fundraiser for Doctors Without Borders.
Jenkins and Schwartzman met up with other climbers who've signed up for the adventure -- folks like Tom Dunlap. He's an arborist from Minnesota. This will be his 25th sleepover in a tree.
"I don't bleed. I drip sap," said Dunlap. "It's just natural for me to be up in a tree with old friends and making new friends."
The climbers are eager for you to know an important part of their credo. "There's no harm to the trees," said Jenkins. "Using climbers-spurs like telephone climbers — no-no. That's a no-no. Driving nails and stuff into trees, that's a no-no. We don't penetrate the trees."
Michael Oxman shows how they get the climbing lines over the Sitka spruce branches. The lowest branch is a good 75 to 80 feet above ground level. Hundreds of pounds of equipment get hauled up — safety lines, food, gear for sleeping — in the amazing undertaking.
The pressure was on to get everyone tree-borne before dark, to get them up in the air so high, that you can barely see the tree-top encampment from the ground.
It may be pull and push all the way, but these experienced climbers seemed to zoom up the trees. "This is great. It's amazing to be able to see across different textures of the trees...different colors," said Oxman.
For Schwartzman, everything was more difficult. With little use of her legs, her arms did all the work. She inched up the rope, with Jenkins staying close as possible. It took her an hour to reach the canopy camp.
But what a campsite awaited her. Tree hammocks and "tree boats" slung between the branches like so many cocoons.
"Holy tamales," exclaimed Schwartzman. "How far have I climbed?"
"Being in the canopy of a tree is so totally different," said Jenkins. "It's very peaceful. It's extremely calming. It's a place to be rather than a thing to do. It's hard to explain. It's sort like coming home."
The climbers ate their supper before sleeping in the cold, wet night. On the next morning, golden and bright, the high-flying friends' next task was to climb down the tree.
For Schwartzman, this became the hardest part of the climb. She had to use different gear to come down than what she used when she went up. Despite all the hours of practice, making the transfer proved difficult.
"I've got to hold onto something," said Schwartzman. "My hands are so cold. My hands are so cold."
The struggle went on for 20 tense minutes. But "the tough old bird" did not disappoint. Schwartzman lowered herself to the ground and started to cry.
Next, Jenkins landed softly to the ground. However, his voyage was not yet over. "I have a question for you," Jenkins told Schwartzman. "I have a big question for you: Will you marry me?"
Jenkins showed a bird's-nest-shaped ring to Schwartzman. Did she say yes?
Well, they will be married on Saturday. Under a tree, of course.