It is feared that James "Kiwi" Oroc (Johnson) crashed in Nevada, where he was paragliding at the time, worried friends say.
Well-known in the paragliding community in the US, Oroc was last seen on Saturday, local time, southwest of Eureka County in Nevada.
An extensive search and rescue operation is now under way in the area of Nye County, near the Eureka County.
Searchers have been scouring the terrain by foot and by air, the Eureka County Sheriff's Office said.
The Eureka office was assisting the Nye County Sheriff's Office, with the latter being in charge of the search and rescue operation.
More than US$50,000 ($77,000) has already been raised to support search efforts for the journalist, photographer, and artist on a GoFundMe page set up by worried friends nearly 12 hours ago.
Funds raised on the page would go towards the costs of fuelling the air searches in the area.
Searchers were working on the theory that Oroc had been separated from his GPS tracker and may have fallen, the page said.
"If you don't know 'Kiwi' you've probably read his pieces in Cross Country magazine and Free Flight. He's been a friendly big personality in paragliding for 30 years," the page says.
"Originally from New Zealand, he lived in Jackson Hole and more recently New Orleans in between flying adventures."
While speaking with paragliding podcast Cloudbase Mayhem last month Oroc said he began paragliding after he moved to Wanaka.
"I was about 17 years old and my friends took me skiing and I'm pretty sure that was the first time I saw somebody flying because guys were flying off the road there in '86 or '85.
"And then the next year I ended up moving to Wanaka for the winter [to] pursue skiing."
That was when I first got into paragliding, with some younger guys out of Queenstown, he told the podcast.
With an elevation peak of 3055 meters, Nine Mile Peak is the highest point in Nevada's Antelope Range, according to mountaineering community website Summitpost.
A number of commercial pilots and paragliders had joined in the search efforts, with three aircraft in the skies just hours into the search.
Since 1998 Oroc has "pursued and reported on the cutting edge of extreme sports" in over 40 countries around the world, his website says.
Oroc's work has appeared in magazines, films, and on MTV Sports.
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A regular contributor to Cross Country Magazine, Oroc had 30 year's worth of experience as a pilot, the magazine shared online.
"We hope he'll be walking out with one hell of a story."
But time was of the essence in the search and recovery efforts, with fires in the area hampering visibility and storms forecast to hit, the post said.
Active in the paragliding community, Oroc assisted search efforts of another paraglider reported missing in Peru in 2011.
He reported on the experience of searching for his missing friend, Xavier Murillo, for Cross Country magazine.
A member of the Burning Man community since 1999, Oroc is also involved in the documentation and advancement of "Alternative Culture", publishing three books on the use of psychedelics.
