In 1819, explorers on Stephen Harriman Long's Yellowstone expedition also made note of the ruin, describing them as "a few miles below Isle au Vache." By the mid-19th century, all traces of the fort were gone. Location The exact location of the fort is not known because of conflicting reports about its relationship to trade with the Kansa tribe. British reports placed it below the confluence of the Kansas River and Missouri in what is today Kansas City. However, most reports place it on the bluffs above the confluence of Salt Creek and the Missouri River just north of modern-day Fort Leavenworth. This was roughly in the same location as a major Kansa village. Lewis and Clark reported visiting this site on July 2, 1804: The French formerly had a fort at this place, to protect the trade of this nation, the Situation appears to be a one for a Town, the valley rich & extensive, with a Small Brook through it and one part of the bank affording yet a good landing for boats. For decades, researchers, archaeologists, and scholars have "flown over [the area] in a helicopter, studied aerial photographs of it, driven around and over it, and walked over practically every square foot of it—and have found no definite trace of [the fort]." In 1987, the magazine Soldiers claimed that David L. Campbell, through the use of template mapping, had located foundations on a bluff that may have been the fort's remains. (This claim was reiterated in 2012 by The Leavenworth Times.) However, this claim has not been verified by archaeological evidence, and in 2004, the Kansas Historical Society claimed that the fort's exact location "remains as one of the active historical and archeological mysteries in Kansas." See also List of French forts in North America References External links Geospectra photos Fort de Cavagnal Forts in Missouri Forts in Kansas Fort de Cavagnal French forts in the United States Colonial forts in Missouri Colonial forts in Kansas 1744 establishments in the French colonial empire