Austin Warnock was hunting for mule deer in the Sawtooth Mountains last week when he stumbled across what he believes to be a lost Russian weather balloon and radiosonde.

“It was in the rocks on a hillside,” said Warnock, a Casa Grande resident.

The radiosonde, an instrument package, was attached via a string to a deflated red balloon.

Warnock, an avid hunter and wildlife photographer, was on a four-day hunting trip for mule deer in the mountains south of Arizona City when he found the device on Jan. 12.

“I got turned around and was going through a canyon when I saw it,” he said.

For several days, he wasn’t sure what the device was.

“I’d never seen anything like it before. I thought maybe it was used for astronomy,” he said.

A switch on the back of the device was still in the on position when he picked it up. He turned it off.

Curiosity about what he’d found prompted him to post a message on a social media chat site, looking for answers.

The post was seen by a Casa Grande woman from Poland who speaks Russian. She identified the writing on the device as Russian.

“It says War Air Strengths/Defense of Russian Federation, but the packaging seems to be very recent,” the commenter wrote. “The other one says ‘Top Secret,’ but I have my doubts.”

A radiosonde is a device usually carried by a balloon into the atmosphere to record weather conditions and transmit data via radio to a ground receiver.

A website listed on the radiosonde,, suggests the device found by Warnock may have been made by German company Graw, a manufacturer of radiosondes that operates stations worldwide.

National Weather Service spokesman Chris Kuhlman said weather balloons rarely travel more than 100 miles from their launch site.

“As for where it was launched, we don’t know, but it doesn’t seem very likely it could have made its way across the Pacific,” he said.

In examining photos of the radiosonde, Kuhlman said it was likely made in Europe.

“It doesn’t look like any weather instruments used around here,” he said.

But Eric Betterton, professor and head of the Hydrology and Atmospheric Sciences Department at the University of Arizona, said that although rare, a Russian radiosonde could wind up in the Arizona desert.

Dust from the Gobi Desert often gets caught in air currents, enabling it to travel across the ocean and into Arizona, he said.

“It could have got caught in a swirling jet stream that carried it across the Pacific,” he said. “Or it could have been launched from Siberia and traveled through the Alaskan Gulf. If it came from eastern Siberia, it wouldn’t have to travel as far.”

Betterton does not speak Russian and could not identify the writing in the photos but said radiosondes originating from the United States are generally smaller and made of cardboard. They often include self-addressed stamped envelopes for their return.

“In 30 years, I’ve only found one, and it was from the U.S.,” he said.

After examining photos of Warnock’s radiosonde, Betterton said he planned to show the photos to his class of hydrology and atmospheric sciences students.

“It’s certainly possible it could have traveled from Russia,” he said. “It would be rare, but it’s possible.”

Although Warnock didn’t manage to snag a deer on this most recent hunting trip — he says mule deer are among the most difficult animals to hunt — he said he’s now learning a lot about radiosondes and weather data recording.

He wonders if someone is looking for the radiosonde he found.

“I’d like to know more about where it’s from, who launched it and if anyone needs the data that’s recorded on it,” Warnock said.