A Near Blast From the Past

In the fall of 1974, rancher George Robinson made an interesting find on an isolated ridge in the southern reaches of Phillips County. On the ridge was an unexploded bomb, about two feet long and four inches in diameter.

According to an account in the Phillips County News on Oct. 3, 1974, Robinson summoned Sheriff Pete Messerly and the two men brought the bomb to the National Guard armory in Malta. An Air Force bomb team from Utah arrived soon thereafter and took the bomb out of town and exploded it. According to a witness, the explosion created only a small fire.

The Air Force told local authorities that the bomb was likely dropped by a balloon nearly three decades earlier during World War II. The suspected source of the bomb: Japan. Decades after the war, Robert Mikesh, a researcher connected to the Smithsonian Air and Space Museum, using declassified war-time records, compiled a historical account of the use of balloon bombs by the Japanese and described them "as the first successful intercontinental weapon."

A list assembled by Mikesh also revealed that Robinson's 1974 discovery was not the first in or near Phillips County. A Japanese balloon was discovered near Hays in February 1945, with another near the now-gone Phillips County community of Legg in March of that year. A balloon bomb with a complete undercarriage was found near Turner in April 1945, while a largely intact balloon-bomb was discovered near Tampico, in Valley County, in June 1945.

It is estimated that Japan launched about 9,300 balloons, all about 33 feet wide, each carrying about 800 pounds of bombs, incendiary devices and ballast late in 1944 and in the early months of 1945. Of that number, about 300 were sighted or found in North America. In Montana, remnants of 32 balloon bombs have been discovered. In some cases, the balloons were largely intact, while in others, only fragments or small pieces were found. Montana trails only Oregon in the number of known balloon-bomb incidents in the U.S.

The first balloon-bomb incident in the U.S. is believed to have caused an explosion near Thermopolis, WY, in December 1944. The second, near Flathead Lake in northwest Montana, came about two weeks later, when a father and son gathering wood found an intact balloon with a rising-sun symbol on its canopy. The two notified the sheriff, who summoned the FBI.

Shortly after the discovery of the apparent balloon bomb in the Flathead, the federal Office of War Censorship, established after the 1941 attack on Pearl Harbor, asked the news media to not publish accounts of the balloon bombs, claiming sharing such news would help the Japanese. An account of the first Montana balloon discovery appeared in several newspapers across the U.S., but for months, even as remnants of additional balloon bombs were found, there was very little public mention of the incidents.

The unmanned balloons, filled with hydrogen, had no propulsion system, instead relying on the "jet stream," the narrow band of westerly winds to carry them across the Pacific at altitudes of 20,000 to 40,000 feet and at speeds of more than 200 miles per hour. Some believe the incendiary devices on the balloons were intended to start forest fires in the Pacific Northwest, prompting the U.S. military to shift manpower to fight the fires and possibly impede the development of weapons. Another likely motive behind the balloons? The desire to spark fear.

On May 5, 1945, an incident in southwest Oregon, altered the historical course of the balloon-bomb saga. A group of two adults and five children on a Sunday school outing came across what was believed to be a balloon bomb. Moments later, the device exploded, killing five children and one of the adults. The six deaths are believed to be the only World War II-related civilian deaths on the U.S. mainland. Almost two weeks after the deadly explosion, the U.S. government issued a vague statement about the event and warned people of "the danger of tampering with strange objects found in the woods."

While historians later noted that the voluntary censorship of news about the balloon weapons made it difficult to warn the public about the explosive objects, government officials defended the practice, saying the lack of news coverage about the impact of the balloon bombs "had baffled the Japanese, annoyed and humiliated them, and has been an important contribution to security."

After the war, Japanese officials involved in the balloon program said they had been monitoring U.S. radio broadcasts as a way to measure the effectiveness of the bombs. The news blackout led them to conclude "that the weapon was worthless and whole experiment useless."

While a significant number of the balloon bombs launched by the Japanese likely never reached North America, uncertainty remains as to whether there are more unexploded wind-driven weapons lingering in Montana and elsewhere. ( A hunter found part of balloon bomb in British Columbia in 2019.) The possibility of more unexploded bombs like the one found in 1974 by George Robinson adds intrigue to what Michael Collins, director of the Smithsonian Air and Space Museum in the 1970s, described "as one of the most bizarre and obscure chapters of modern warfare."

Publisher's Note: The story above was written by Butch Larcombe, the great-grandson of John Survant, who started the Malta Enterprise and the Phillips County News. His father, J.R. Larcombe took over ownership of the PCN in the 1920's, and Butch's father Jim Larcombe bought the PCN in the 1950's and ran the paper until October of 1974.

Butch worked as a reporter and editor at daily newspapers in Missoula, Great Falls and Helena, and was the editor of a statewide magazine, all over a 30-year period.