Zipline Treetop Adventure is a sensational way to see the scenery of the Pemigewasset Valley and White Mountains.

Alpine Adventures Outdoor Recreation

LINCOLN, N.H. — Am I really going to do this? That’s what I wondered as I stood on a wooden platform while harnessed to a cable 50 feet up a pine tree.

Before me stretched a gorgeous view of the Pemigewasset Valley and the White Mountains beyond, but fear had narrowed my focus to the cable at my feet dropping at an impossibly steep angle down Barron Mountain.

“Did I tell you I’m afraid of heights?” I asked Al Guilbeault, director of operations at Alpine Adventures and my guide through a hands-on attraction called a Zipline Treetop Adventure.

“There’s no shame in that, it’s a defense mechanism,” he said.

Maybe it was machismo, or the gleeful exuberance of the four young local women also on the tour, but defense mechanism be damned! I took a step off the platform and slid down the mountain at treetop level, my heart thumping so loudly it nearly drowned out the whir of the pulley above my head.

One hundred feet below I came gently to rest in the welcoming arms of a helmeted guide. So far so good.

Alpine Adventures opened the zipline treetop cable system in late August of last year. As Guilbeault explained, ziplines were developed by biologists, who set up a cable and pulley system in a Costa Rican rainforest so they could study wildlife in the jungle canopy. The technology has been adapted for thrill-seekers and there are now three or four zipline courses in the United States. This one was the first in the Northeast.

The course descends a half mile with seven lines connected by platforms, walkways, and a rope bridge.

As we tugged on our helmets and harnesses, I met Justin and Liane Joly, a young couple from West Warwick, R.I., who were celebrating their first wedding anniversary.

“You look nervous,” I said to Justin.

“I’m terrified,” he said. “She’s the adventurous one.”

Elvis Presley singing “All Shook Up” blared from the stereo as we hopped into an open-sided six-wheel-drive Swiss Army transport truck for the 10-minute ride up the mountain.

As my helmeted head bounced off the roof of the truck, I was having my doubts. If the look in his eyes was any indication, Justin Joly was too.

It’s worth noting that ziplining calls for no special skill or strength, and that the cables can hold up to 17,000 pounds. Thus reassured, we began what became a three-hour trip from fear to exaltation. (The young women were fearless from the start, hooting and hollering and twisting on their harnesses each time they dropped.)

At the first zipline, your speed is controlled by a drag line held by a guide. During the next six drops, gravity controls your speed. Safety comes first. Even when standing on a platform, you’re fastened to a cable by a safety line.

“Wait until you see the last one,” said Guilbeault. “It’s great. You drop almost like a free fall before the cable takes hold.” He explained we might reach speeds of 35 miles per hour on the descent and that there was an escape trail back to the truck if we chickened out.

Uh-oh.

The second drop was 250 feet long and 65 feet high at its peak. The landing is on a platform 50 feet up a pine tree, where a guide hauls you in.

The trip down was magical. All fear escaped as I whizzed though the canopy of 70-foot oak trees, some just beginning to show a trace of fall orange. The bird’s-eye view was breathtaking — maybe a little too breathtaking: I failed to grab the outstretched arms of the guide trying to catch me on the platform at the end.

I slipped backward and ended up suspended above the forest floor, without the momentum to go up or down, dangling motionless from the cable 65 feet above the ground. And you know what? I could have stayed there for hours. The scenery was gorgeous and now I know what it’s like to be a bird on the top of a tree.

I was “rescued” by Guilbeault, who placed another pulley with a rope tether on the cable. He then descended to the forest floor and pulled the tether until his pulley backed up to mine. He then pulled me up to the platform, where the guide retrieved me.

The next drop I found particularly frightening, a slow-motion sit-down takeoff from the platform for a 75-foot slide down the mountain to a rocking rope walkway 25 feet long and familiar to anyone who has watched old jungle movies. But the bridge was a cakewalk. I was harnessed to a cable above, so there was nothing to fear.

I aced the next few jumps — 330, 500, and 200 feet — and then we arrived at the big kahuna, the last drop, about 400 feet with the heart-stopping fall at the beginning.

There would be no shame in dropping out. What was there left to prove?

As the young women in our group whooped onto the platform behind me, I looked to the Jolys for guidance.

“Why not?” said Liane. She leaped off the platform and screamed as she dropped.

So 400 feet down the mountain I zipped. It was, as the Jolys agreed, “awesome.”