The water head of the Wawagosic River is located on the border of the administrative regions of Nord-du-Québec and Abitibi-Témiscamingue. The Wawagosic River originates in a small marsh north of Authier Lake, in the unorganized territory of Lac-Chicobi, Quebec, west of the Octave River (Harricana River) and north of Chicobi Lake. This sector is included in the Esker-Mistaouac's proposed biodiversity reserve. The head of the river drains the waters of the western slope of Saucer Hills (altitude: ) and Mount Plamondon (altitude: ).
