Wind-driven balloon bombs
Boaters know all about South Dakota wind. They can tell you how quickly a pleasant afternoon can turn into a rough outing, bouncing on one big wave after another, racing back to the dock before a rapidly-moving storm arrives. The Japanese can tell you about wind, too. It is how they attacked South Dakota during World War 2.
Japanese meteorologists were well-ahead of the rest of the world in the study of jet streams, the bands of fast moving wind that encircle the globe, six to nine miles above the surface. They figured out how the polar jet stream could be used to blow balloons from Japan to the United states. So in the latter stages of the war, the Japanese launched about nine thousand balloons carrying bombs, hoping for the ultimate sneak attack. Just under three hundred are known to have completed the trip over the Pacific Ocean to the United States. Some landed in South Dakota.
One of those balloons was found in Hand County by Ronald Waring, who discovered it fifteen miles south of Ree Heights in March, 1945. Unaware of what the object was, Waring put it into the trunk of his car and took it home. When found, one bomb still dangled from what remained of the balloon, which had been about 35 feet in diameter. About 2000 feet of rope had been used to hold the apparatus together. Parts of the balloon itself were found, and they revealed it had been made of heavy paper. What was presumed to be the main part of the balloon was later found in Beadle County.
Martha Tamblyn wrote in the Miller Press: "Curious to know what was in the oblong tin box which was still attached to the wreckage, Ray Rogers pried it open with a pen knife. It was then decided it was something more than a toy, and authorities were notified of the discovery."
The South Dakota Attorney General's office picked up the balloons remains, and put them in Governor M.Q. Sharpe's reception room for safekeeping. The Miller newspaper did not report the finding until the war was over - a self-imposed censorship agreed to by several South Dakota newspapers. That way the Japanese would not know their bombs had successfully reached the US. Yet the balloons caused little damage, and the only fatalities were a minister's wife and five children, killed when they discovered a balloon bomb in Oregon in May, 1945. Officially, between November 1944 and August 1945, 285 balloon incidents were recorded in North America. Most of the balloons were 32 foot wide, mulberry-paper bags filled with hydrogen. The bombs dangled below. Eight balloon bombs landed in South Dakota.
Remains of the Ree Heights balloon, from the South Dakota State Historical Society
Lawrence H. Larsen wrote in South Dakota History: "While the balloons appeared harmless - one South Dakotan unknowingly carried a balloon bomb many miles over bumpy back roads in the trunk of his car, and another allowed his children to use a balloon bag for a doll house - they could be very deadly. The charge from one, exploded with a dynamite cap by an army intelligence officer at Rapid City, tore a hole in the ground three feet deep and five feet in diameter." It took four to six days for the balloons to float in the eastward jet stream from Japan to this country. A clever ballast system allowed the balloons to remain at a constant altitude of 20-25 thousand feet. "The fact that they were able to achieve such extended periods of flight was monumental at that time," said former Raven Industries executive James Winker, himself a balloonist. In 1947, while working in Minneapolis, Winker helped launch a recovered Japanese bomb balloon that was re-fitted to carry people.