Pedro Portillo Silva (August 1, 1856 - June 15, 1916) was a Peruvian explorer, military officer, and civil servant. Born in Huacho, Portillo joined the Peruvian army at 23 during the War of the Pacific (1879 - 1884). He fought in three battles. After the war, Portillo became the sub-prefect of Chancay, the prefect of Ayacucho (1896 - 1900), the Minister of War and Navy (1900 - 1901), and finally the Prefect of Loreto (1901 - 1904). It was during these years that Portillo began exploring the Amazon. While the Prefect of Ayacucho, he explored the department, built bridges, established communication routes, and founded several river port towns. When he was the Prefect of Loreto, he undertook the same mission of exploring the department and navigating many of its rivers. He drew maps of the Putumayo River and the northern region of the department of Loreto and contributed to the Atlas of the Department of Loreto. During his tenure as Prefect of Loreto, Portillo commissioned numerous maps of the department and the wider region made by a handful of cartographers, including Carlos Hoempler (1864 - 1936), Camilo Vallejos, and Rafael Baluarte. After his time as Prefect of Loreto, Portillo served as Minister of Public Works and Development (1906 - 1908), Senator for Loreto (1913 - 1916), and another stint as Minister of Public Works and Development (1913 - 1914).