WATERVILLE — Five years ago, Vassalboro resident Ken Walsh traveled to the Rogue River in Oregon for a relaxing rafting excursion.

“We were going to have a nice family trip,” he said, “but it was a family vacation turned wrong.”

Walsh’s young cousin was bitten by a rattlesnake, and, in a frantic effort to alert emergency responders, Walsh was nearly killed in the backcountry.

The ordeal has been retold since then in an episode of the national television program “Got Home Alive,” which airs at 4 p.m. today on the Travel Channel (cable Channel 49 in Portland).

The story takes place in 2006.

During the Independence Day weekend, Walsh and 11 others planned to raft through a 40-mile section of white water. The river winds through canyons and wilderness in southwestern Oregon.

At the end of the first day, the rafters hauled their boats onto a beach to make camp. While the adults set up tents, the children played.

Walsh’s cousin, Spencer Funk, was 11 at the time. He was typical for a boy his age, Walsh said.

“He decided to find a reptile (so) he could chase the girls with it,” Walsh recalled.

Spencer grabbed what he thought was a garter snake. Instead, he picked up a young rattlesnake, which bit him on a finger.

The campers had heard a story about an adult who had suffered a fatal rattlesnake bite in the canyon a month earlier, Walsh said. They knew Spencer’s injury was life-threatening and time was of the essence. The adults gathered to discuss a plan.

The campsite was at the bottom of a steep canyon with no cellphone service. The sun was setting, and paddling downstream through Class III, IV and V rapids in darkness would have put everyone in jeopardy. The only way to get help was on foot.

Spencer’s father, Roger Funk, was recovering from a recent foot injury. Walsh, who was 46 at the time, was an avid runner and a former gymnast.

“Roger looked at me and said, ‘I need you to run out of here,’ ” Walsh recalled. “So the adventure began.”

Walsh put on a headlamp and sandals and began running a trail that gradually took him out of the canyon and onto a ridge overlooking the river. In many places, the trail skirted 100- to 200-foot sheer drops.

“The trail was right on the edge — right on the edge,” he said.

It was night, and Walsh was running fast through darkness. There was no moonlight, and a thunderstorm was brewing nearby.

The wilderness area is also rife with bears and mountain lions, he said.

“It was eerie,” Walsh recalled, “but you get in a mode where you don’t think about those things. I just put my head down and kept trucking along. I was really booking it.”

Walsh almost didn’t make it.

About two miles into his run, Walsh tripped on a tree root and stumbled toward the cliff’s edge. One hundred feet below, the Rogue River roared over Class V falls.

“I started going over the edge, and at that point I was just reaching for anything,” he said, “and luckily, there was a tree limb that was hanging down.”

For a moment, Walsh was dangling over a cliff edge.

“I remember my feet were hanging,” he said. “There was air underneath me.”

Walsh said his gymnastics instincts kicked in.

“I just swung back up and just kept going,” he said.

Walsh ran the trail for nearly 40 minutes, then came to a logging road. Minutes later, he saw a parked pickup truck. Inside the truck bed, local resident Randy Stark was sleeping.

Walsh explained the situation and Stark drove them to a nearby ranger station. From there, they called an ambulance in Grants Pass, about 45 minutes away. When the ambulance arrived, it was apparent that no one knew how to get to the campsite.

“No one had a clue,” he said.

Stark had a suggestion. He recalled a trail he’d hiked in the region 15 years earlier and thought it might be worth a shot. The problem was, Stark wasn’t exactly sure where the trail was.

Stark and Walsh drove around the area, with the ambulance following close behind. Stark stopped at a gated trailhead that looked promising.

“He said, ‘I can’t guarantee this, but let’s just go down the pathway to see if this takes us to the river,’ ” Walsh recalled.

The hunch paid off.

“It led right to the campground,” Walsh said. “It was amazing.”

It was 11 p.m. when they arrived at the camp. By the time Spencer was carried on a stretcher out of the wilderness and driven to the emergency room in Grants Pass, it was 4:30 a.m.

He recovered from the snakebite, but to this day his finger remains numb, Walsh said.

Earlier this year, a producer for “Got Home Alive” contacted Walsh about filming the story. A portion of the episode was shot this summer during a family reunion in Cortlandt Manor, N.Y.

Then, in July, Walsh and the Funks returned to the Rogue River with helmet-mounted video cameras to retrace their rafting trip and document it for the show.

Walsh hasn’t seen the episode yet, but he soon will. At 4 p.m. today, the Silver Street Tavern will host a viewing party. The event is free and open to the public.