
Poling in the Missouri Shallows. In May 1804 the Corps of Discovery was on the Missouri River in a keelboat whose sail often had to be reefed in favor of men using poles. (Ed Vebell/Getty Images)
Ed Vebell/Getty Images
Poling in the Missouri Shallows. In May 1804 the Corps of Discovery was on the Missouri River in a keelboat whose sail often had to be reefed in favor of men using poles. (Ed Vebell/Getty Images)
Ed Vebell/Getty Images