Roosevelt–Rondon Scientific Expedition

The Roosevelt–Rondon Scientific Expedition (Portuguese: Expedição Científica Rondon–Roosevelt) was a survey expedition in 1913–14 to follow the path of the Rio da Dúvida ("River of Doubt") in the Amazon basin. The expedition was jointly led by Theodore Roosevelt, the former president of the United States, and Colonel Cândido Rondon, a Brazilian explorer who had discovered its headwaters in 1909.