Lee Gatchell saw the snake quiver. It lashed out too quickly for him to see the strike, but he felt it just below his right knee, on his outer calf.

It was the last day of 2007, the last day of the 14-year-old Capital High freshman’s Costa Rican Christmas vacation.

In the blink of an eye, it became the first day of a 26-day marathon to save his life and leg.

This was the second visit Lee’s family — mother Tamara Blank, dad John Gatchell and sister Jaya — took to the lush rainforests of Costa Rica, a Central American country about the size of Vermont, home to 4 million people, white sandy beaches and a family-oriented society that made the Gatchells comfortable.

For 10 days, with aunts, uncles and their grandmother, they stayed at one of three guest lodges at the southwestern tip of Costa Rica. The family played in the surf and hiked through the forest, marveling over an abundance of sloths, macaws and other exotic species. On the final day, Lee planned one last adventure, rappelling down a series of four waterfalls, connected by short walks through the creek feeding the falls.

Eight tourists signed on for the trip, but six backed out at the last minute, leaving Lee, a young woman and two guides to set out on the morning excursion.

The first waterfall was narrow like a slot canyon, with the water falling 20 to 30 feet. The second was similar.

“They start out with an easy one, then a relatively easy one to gauge how good you are,” said Lee, a dark-haired, wiry youth with a knack for deadpan humor and a vocabulary hinting at a maturity beyond his years. “Then there is a third waterfall, where you couldn’t see the bottom from the top because of a bend. That’s about 50 feet.”

With characteristic self-appraisal, Lee said number three was a little scary — he stumbled a bit — but not a problem. The final pitch was just ahead, 70 feet of water thundering into the pool below. The real thing.

It was shortly after 9 a.m.

He was focused as he jogged down the creek to the final waterfall. Lee almost didn’t hear a guide yell “Watch out!” or something like that.

It was too late.

“I looked down and there was this snake, coiled up. It was the color of sand with a diamond pattern on its back.

“... It looked like the snake quivered or shook. Then I saw two bite marks, or slashes. The weird thing is I didn’t feel it bite me. They said it went in this deep,” Lee said, holding his finger and thumb a good inch apart.

Lee had chanced upon one of the most feared snakes in Central America, the fer-de-lance. It’s an irritable viper that strikes with little provocation, unhinging its jaw to throw forth fangs like a switchblade.

At lengths of up to 5 feet, it’s also one of the largest and deadliest poisonous snakes. The fer-de-lance’s incredibly painful, toxic venom is “hemotoxic,” meaning it causes massive tissue destruction and “hemorrhagic,” meaning it causes profuse internal bleeding. In effect, it works by killing the victim’s veins and capillaries, causing internal swelling so severe that doctors often cut open the skin to relieve the pressure.

In recent years, the ready availability of antivenin has reduced annual fatality rates to five or six people, but it’s not something a guide would typically carry.

They had to move fast.

“I kept going, but they said to sit down on a rock and they pulled a suction thing out and tried to suck the venom out of it. Later I learned that did nothing,” Lee said.

“They started to get me up the hill. I started to faint or go into shock or something. My vision went 2-D — green speckles covered my vision. Even my sense of touch seemed to lose dimension. By then, moving my leg was painful, so I put one arm around their necks and they hoisted me up the hill on a little, tiny trail.”

They reached the wider beach trail, where the other tourist ran ahead for help.

“I pretty much lost control emotionally there,” Lee said quietly. “They had me sit on a beach trail and I calmed myself down, put those emotions under lock and key. It was kind of tough, but I knew the calmer I was, even on the surface, it would be better.”

Lee knew what he was battling. One of his hobbies is studying poisonous snakes.

“I had kind of lost my rationality going up the hill. I keep needing reassurance,” Lee recalled. “You hear about situations where people got bit in the leg, go into shock and a little while later they’re dead.”

It took 15 minutes to reach the lodge.

They threw Lee into a waiting vehicle and raced down a bumpy road strewn with potholes and creek crossings, stopping to pick up Lee’s grandmother, who happened to be hiking nearby with an aunt and uncle.

They met up with an “ambulance” — a glorified van with a gurney that kept sliding around — and transferred Lee and his grandmother. By this time, he was throwing up.

“I think it was a combination of nerves, I get motion sickness, and the venom,” Lee said. “I asked my grandmother to tell me a sailing story to make me feel better.”

Within an hour, they were at the clinic, less than two hours after Lee was bitten. The doctor took one look at Lee and started the antivenin.

The grandmother counted 15 or 16 vials.

Meanwhile, John and Tamara were near the base of the fourth waterfall, waiting to watch Lee make the final rappel. After he didn’t appear in the expected time frame, Tamara started walking back to the lodge.

“I met the owner, and he said ‘Your son’s been bitten by a snake.’ I said ‘A bad one?’ He said ‘Yep. A terciopelo,’ ” Tamara recalled.

“But he said it was a dry wound, a glancing blow and we had to wait for a taxi, which would take about 20 minutes.”

The lodge owner continued down the trail to find John.

“The second I saw he was out of breath I knew something was wrong,” John said. “I ran up the trail head and found Tamara, then started packing. Everybody there said they couldn’t believe how calm Lee was when they were loading him up.”

Knowing that there wasn’t anything she could do, and that her mother was with Lee, Tamara took a shower while John started packing some clothes.

The guides returned to the waterfall, found the snake and killed it. They brought it to the lodge, where John took pictures. It was a big one, five feet long, with two-inch fangs.

Once at the clinic, John and Tamara were shocked at what they found.

“The last time I saw him he was an eager young man excited to go waterfall rappelling. The next time I see him he’s pale and frail with an IV and all groggy because he’s not only been given anti-venom, but also some kind of antihistamine thing,” Tamara said.

“I just wanted them to give me a stupid painkiller and some water,” Lee interjects. “I guess they didn’t want to give me water in case they had to put me in surgery.”

They decided to continue his treatment at a rural hospital in Golfito, which meant putting Lee in a small boat for the trip across Golfo Dulce. By this time, it was about noon.

“They had neutralized the venom, mostly, but my leg was still swelling. My foot was purple and cold and I couldn’t feel it,” Lee said.

John showed the snake photo to the doctor. She winced and turned away.

“She knew exactly what kind of snake it was, and when she saw how long it was, she agreed he would get the best help at this other hospital,” John said. “But Lee didn’t want to be moved.”

As a dozen more vials of antivenin were pumped into his body, the family decided to transfer Lee to a larger hospital at San Jose, but that meant chartering a plane. The 210-mile flight had to take place before dusk, because the landing strip didn’t have any lights.

After a flurry of late afternoon phone calls by their friend and lodge owner Joel Stewart, they took off in a private plane just before sunset. Once the word got out about Lee’s bite, they were cleared for an emergency landing after the hour-long flight, hitting the tarmac at dusk.

A waiting ambulance rushed Lee to the San Jose hospital, they met Dr. Hugo Villegas del Carpio, who Lee considers his savior.

“He’s just amazing. Every time he would come in he would give us a very thorough explanation of what was happening,” Lee said. “He also told us what the problems were, and he mentioned several.”

One issue is the venom stops or slows down blood’s ability to coagulate; in Golfito, they timed Lee’s rate at an unheard of two minutes. By the time they reached San Jose, it was down to 32 seconds, which is still considered a long time to coagulate.

But Lee’s main problem was the swelling. He couldn’t feel his toes, and his right foot was purple, cold and hard as marble.

So even though his blood wasn’t coagulating correctly, surgeons still needed to cut open Lee’s right leg from ankle to thigh to relieve the pressure.

“I was scared but understood that surgery by far was my best option at the time,” Lee said. “Then they finally started giving me pain killers after Dr. Villegas finished his analysis.

“I don’t remember anything after that.”

His parents do.

The doctor’s also sliced open Lee’s inner calf from ankle to knee. An incision was made near his right arch in his foot.

“The fang went into one of his calf muscles — you have three — and those are the muscles involved in lifting your foot and your ability to walk,” Tamara said. “Fifty percent or more were black, affected by the toxin.”

“The fatty tissue in the area was just brown fluid,” John interjected.

“It washed out like water when they opened him up,” Tamara added.

“But they told us only time would tell,” John said.

Lee’s incisions weren’t stitched together, because surgeons had to go back every other day to check the muscle and let the toxins drain. During this time, they needed to watch for the potential recirculation of venom.

“A pocket of venom could be trapped for days in tissue, and as dying tissue is cleared away, the venom could get back in my system,” Lee said matter-of-factly. “That would be serious.”

“I remember saying a lot of prayers,” Tamara added softly. “I felt so helpless. It went from being a ‘glancing blow’ to ‘your son may never walk again’ in one day.”

During all this, Lee displayed a remarkable calmness — so much that his parents weren’t sure if he understood the depth of the danger.

So as he dozed off and on in the recovery room after the first surgery, Tamara sat near his bed and told him small bits of information, trying to be honest but not overwhelm him.

To Lee, though, all that mattered was he was alive.

“I was like — lose the leg? Who cares now? I couldn’t do anything about it,” he said.

The next few days were a blur of surgery followed by a day of recovery. In all, Lee went into the operating room five times. The fourth surgery closed the inner wounds.

In the fifth surgery, doctors closed the outer wounds and performed a skin graft, where they used a tool — they described it like a high-tech potato peeler — to remove skin from the back of Lee’s leg, then affix it to his calf where the skin no longer could stretch across his muscle.

“That was the most pain I was in since the first day,” Lee recalled. “The skin is full of nerves and they really didn’t like being chopped in little pieces.”

Lee counted 130 staples holding his leg together.

The graft took. Then it was onto two weeks of physical therapy.

Finally, 26 days after their vacation was supposed to end, Lee’s plane touched down at the Helena airport. He was greeted by friends and family holding banners, as well as shocked looks when they saw his horrific wounds.

Lee often wears shorts, even in the below-freezing weather, since the doctors told him pants can rub against the wound and irritate it, opening the possibility of an infection.

He returned to school right away, trying to make up the boxcar load of homework awaiting him. Like a typical teen, he grouses that even his Spanish teacher won’t give him extra credit for all the new words he learned, most relating to emergency medicine. However, he is allowed to substitute physical therapy for gym class.

And one day — probably not soon, but one day — Lee plans to return to visit his newfound friends in Costa Rica.

“But I think I’ll do a little less hiking and a little more sticking to the beach,” he said with a smile.

Reporter Eve Byron: 447-4076 or eve.byron@helenair.com