Stratobowl
Coordinates: 43°58′36″N 103°20′43″W / 43.97668°N 103.3452°W
The Stratobowl is a compact natural depression within the limits of Black Hills National Forest in South Dakota, south-west of Rapid City. In 1934–1935 it housed a stratospheric balloon launch site, initially known as Stratocamp, sponsored by the National Geographic Society and the United States Army Air Corps. In 1956–1959 the site was reused by the U.S Navy Project Strato-Lab.
In 1934 the NGS and Air Corps co-sponsored the Explorer, a manned high-altitude balloon capable of stratospheric flight. After the crash of the Soviet Osoaviakhim-1 that nevertheless set an altitude record of 72,178 feet (22,000 m), the sponsors redefined their primary objectives from record-setting to scientific research and tests of new navigation instruments. Air Corps Capt. Albert William Stevens, Capt. Orvil Arson Anderson and Maj. William E. Kepner were selected to fly the Explorer. Kepner and Anderson, experienced balloonists, were in charge of locating a suitable launch site. According to Kepner, an ideal site would be a or canyon, a clear grassy valley encircled with rocky ridges high enough to shield the tall balloon from any wind. Ideally, the launch site it would have a high-voltage electric line, road and rail access, "and a trout stream". Kepner and Anderson eventually located their dream canyon near Rapid City, South Dakota. City officials, fascinated by the expected publicity campaign, agreed to build a road and electric line.
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