In 1742 two sons of the explorer Pierre Gaultier de Varennes de La Verendrye met an indigenous nation they called the Gens de l'Arc somewhere along the middle Missouri River near present-day Pierre, South Dakota. Louis-Joseph and Francois were searching for the mythical Sea of the West, and the former asked the chief of the Gens de l'Arc if he "knew the white people of the seacoast." The chief replied that "[t]he French who are on the seacoast are numerous" and have "many chiefs for the soldiers, and also many chiefs for prayer." The chief was most likely describing an event that had occurred over twenty years earlier: the destruction of the Villasur Expedition on the banks of the Platte and Loup rivers in present-day Nebraska. It was the last expedition of its kind until fears of Zebulon Pike inspired another Spanish march to the northeast. In 1720 Pedro de Villasur led forty-five Spaniards and sixty Pueblo auxiliaries out of Santa Fe to win Indian allies and to gauge the French presence in the Great Plains. Pawnee Indians, perhaps with the help of a few French traders, destroyed the expedition near the confluence of the Platte and Loup rivers, leaving only fourteen survivors to report back to Santa Fe.