National Forest officials were aghast to learn Monday, March 13, that the beauty of Ortega Falls in the mountains above Lake Elsinore is attracting not only nature lovers, but also thrill seekers.

Photographs and videos posted online – recently and in years past – show people tightrope walking directly over the waterfall, a popular destination off Ortega Highway, officially known as Highway 74, which cuts through the Santa Ana Mountains and Cleveland National Forest and connects Riverside and Orange counties.

UPDATE: Here’s what the men who ‘highlined’ over Ortega Falls had to say about the extreme sport

One such photo started circulating on Facebook over the weekend. One commenter on the post feared that sharing the image online would attract the attention of law enforcement.

Websites devoted to the extreme sport known as highlining describe the mechanics: Highliners string a thin, springy band between two points at a great height, sometimes hundreds of feet up, and carefully walk across it, often using a safety harness in case they slip. It’s popular in places with magnificent vistas such as Joshua Tree and Yosemite national parks, where rules are in place to protect both highliners and nature.

Cleveland National Forest spokeswoman Olivia Walker said officials there knew nothing about the pastime, which she said was unsafe and that now has their attention.

Installing the roping system is illegal, Walker said.

“This is not something we would promote or authorize,” she said. “This isn’t something we would ever market or encourage.”

Walker said forest officials would contact the Riverside County Sheriff’s Department and figure out what action to take themselves.

“If this is an ongoing issue … we really need to go out and look at this, who’s setting this up, should we have someone out there on weekends,” she said. “Because if something went wrong, we would be dispatched out there and a helicopter from the Sheriff’s Department to do a rescue.

“For safety issues, there’s a million reasons why we need to make sure this is not a continuous thing,” she said.

The revelation of the highlining comes in the same month that a dirt biker was filmed jumping over Highway 60 in the Badlands east of Moreno Valley. Caltrans workers quickly destroyed the ramp that was built for the stunt in an attempt to prevent anyone from repeating it.

Ortega Falls is visible from Ortega Highway, Walker said, prompting many motorists to pull over and take pictures. The area has been drawing larger crowds lately because rain has swollen the waterfall, Walker said. Now that spring-like weather has sprung, the nearby trails and campgrounds were full this past weekend, she said.

One Facebook photo album posted publicly on Sunday shows several different people walking across a rope that had been strung over the waterfall. They are tethered to the rope.

“I have come to build a bridge. Peace and love flowing as the water here,” wrote the person who posted the pictures.

One person tagged in some of the photos noted that they were “Not too high, around 20ish meters” or about 65 feet up.

Another person, who could not be reached for comment Monday, posted several photos and videos of his own Sunday.

“Here’s a little bit of what today looked like. A lot of fun and peacefulness with some amazing people walking awesome lines! Thanks to everyone who took part and raised the stoke,” he wrote.

The daredevils aren’t the first to try to feat. A search on Facebook turned up another similar photo posted in December. Its caption noted the rope was 730 feet long – about the length of 2 1/2 football fields.

And a YouTube video from 2013 titled “Tightrope walking at Ortega Falls in Santa Ana Mountains” shows a person waving his arms for balance as he navigates the span. Two people, one with a camera, await him on the other side.