Two videos posted online in the past week appear to show an arch and a hoodoo being blown up in a slickrock desert — and the video titles claim they are in Utah.

But an eagle-eyed hiker recognized that the background scenery in both videos may be the view from a popular overlook at Arches National Park — an image on which the exploding rock formations appear to be superimposed.

Meanwhile, multiple experts on southern Utah’s wild lands said they don’t recognize the formations themselves. Officials with the state and the U.S. Bureau of Land Management said they are trying to learn if the sites are actually in Utah. And special-effects professionals who reviewed the videos say they were “very convincing,” but they could be digitally manipulated.

The biggest sign of a hoax appears to be the background scenery, which hiker Jamal Green recognized from his many long-distance treks across southern Utah as the view from the Petrified Dunes Viewpoint, just off the main park road at Arches.

“I’m fairly certain that elements of the background are shot from [the viewpoint],” Green said, providing a photo of the scenic view along with stills from the two videos:

(Photo courtesy of Jamal Green) A view from a popular overlook at Arches National Park appears to have been the backdrop for what likely are hoax videos purporting to show Utah rock formations being blown up.

The color is lighter and the image grainier on the video background — and there are elements to the video’s background scenery not in Green’s image from Petrified Dunes. But the silhouette of a landmass in each of the videos closely matches the view at Arches.

A 360-degree video shot from the spot shows neither the arch nor the hoodoos that appear to explode in the videos.

The seemingly-mismatched background scenery is not the only clue that the footage was altered, said Clark Schaffer, who owns Schaffer Studios in Spanish Fork and has worked for major studios in Hollywood, developing special effects for such blockbusters as the “Iron Man" and “Star Trek” movies.

In the hoodoo video, the camera jostles dramatically at the moment of explosion — too dramatically to be a natural reaction since the person holding the camera appears to know the explosion is coming, Schaffer said. That could “hide something in the blur of the motion,” he said.

In the video of the arch, a person's head inexplicably pops into the frame, sideways.

"If I were making an effects shot, I'd include something like that just to make the audience think it's real," Schaffer said.

Christian Madsen, an animation expert who has produced videos for Real Salt Lake and the Utah Jazz, noted the head’s strange path around the frame. He said he suspected the head was a still image “added in [post-production] with poor keyframing in the animation.”

Moments later, the camera bobbles, and the distant background moves a bit too “tightly in sync” with the foreground of the landscape, Schaffer added.

"I just would believe we'd see a little separation from the background mountain to the foreground mountain," Schaffer said.

"Fakers will shoot static on a tripod for easy compositing” — that is, layering video clips into a single image — “and then add camera wiggle in [post-production] to add realism," Madsen agreed.

At the moment of explosion, which appears to involve three charges, the middle charge "is just blasting straight through," Schaffer said.

"That almost seems like it'd need primer cord wrapped around it," he said. "The point of explosion is questionable to me."

The sound of the explosion also is “suspect,” Madsen said. “The report from the explosion is heard at the same time as the rock breaks, and the rubble seems oddly quiet,” he said.

Immediately after the explosion, a puff of smoke at the top of the arch disappears like vapor. And right before the explosion, the lower edge of the arch is “wiggling,” as if the image is affected by heat, while no other part of the landscape is, Schaffer said. Those quirks, he said, could be chalked up to poor image quality.

But that poor quality is itself suspicious, he said.

"It looks like old video," Schaffer said. "With everybody's camera shooting 4K now, I would think this would be a higher quality video. They could be hiding stuff in the poor quality of the video."

That said, Schaffer acknowledged, "If it's fake, it's incredibly done." The attention to the rockfall in both videos appears very natural, he said. The rocks interact with the surrounding landscape, moving shrubs and rolling at different speeds down the various slopes.

“The physics of the explosions and the falling rubble are extremely good,” Madsen agreed. “There is software for simulating rock destruction that’s widely available and fairly easy to use.”

"All that said," Madsen concluded, "I'd wager the videos have a 60 percent chance of turning out to be fake, a 30 percent chance of having been filmed overseas and real, and a 10 percent chance of being on the Colorado Plateau and being real."

Both Schaffer and Madsen said there was an even bigger reason than the characteristics of the videos to be dubious: As of Monday night, it appeared no one had credibly identified either rock formation or their general locations in Utah.

The Salt Lake Tribune forwarded the video to rangers at multiple southern Utah BLM offices, and none could immediately recognize the arch or hoodoos. BLM spokeswoman Kim Finch later said that land managers are seeking input from rangers to try to confirm or rule out Utah’s BLM land as home to the pictured formations.

As the videos circulated online, longtime explorers in the area urgently scanned through desert images, trying to confirm whether Utah's beloved landscape had been marred.

A group of about a dozen photographers, hikers and scientists with extensive travel experience in southern Utah reviewed the footage and could not identify either location. That's surprising, said Austrian photographer Martin Pi, who has captured scores of Utah's desert rock formations over many years of visits.

“The arch does look like it should be more popular ... and with the hoodoo [video], the spire in the background should be quite easy to identify — but it isn’t,” Pi said.

Videos that purport to show the destruction of the arch on the left and the hoodoos on the right recently appeared online.

As so many people with a passion for southern Utah’s desert landscape tried and failed to identify the formations, some doubted the video titles' claim that they were filmed in Utah.

"Someone here would instantly know [the locations]," said Dan Bjugstad, an administrator for the 16,000-strong "Grand Staircase-Escalante National Monument and Adjacent" Facebook group. "We spend entire days hiking to every obscure feature we can find. Someone should know it, if it is down there, and if we don't know it, how the heck did some destructive schmuck get there?"

The origin of the videos also is in question. The arch video was posted Dec. 7 and the hoodoo video on Dec. 9, both on YouTube and on the website LiveLeak.com — and both by accounts that have posted no other videos. On YouTube, a poster under the name “Tobias Muir” claimed there are three videos in total, and that “sensitive information” is forthcoming. On LiveLeaks, a poster under the name desdu23419 wrote four days ago that “this was sent to a big news network this morning and leaked.”

Neither account has reported any updates.

The Utah Department of Natural Resources and Division of Parks and Recreation told FOX 13 that they were also trying to determine the authenticity of the videos, and noted that destroying natural rock formations on public land is a crime.