The proposed Upper Harricana aquatic reserve is located between 48°46’ and 50°14’ north latitude and 77°58’ and 78°58’ west longitude. Most of the proposed aquatic reserve lies within the territory of Municipalité de Baie-James, in the Nord-du-Québec administrative region. The upstream part of the proposed aquatic reserve crosses Municipalité de Saint-Dominique-du-Rosaire and the unorganized territory of Lac-Chicobi, in Municipalité régionale de comté d’Abitibi forming part of the AbitibiTémiscamingue administrative region.
The southern boundary of the proposed aquatic reserve is situated approximately 25 km north/north-east of Ville d’Amos.
The proposed aquatic reserve covers an area of 177.2 km2. It forms a corridor that takes in a 200-metrewide strip of land on either bank of the Harricana river, protecting the main bed of the river and riparian habitats over a distance of approximately 190 kilometres. From upstream to downstream, it extends from Obalski lake to the proposed North Harricana river aquatic reserve. The private lands that overlap the 200- metre strip in the upstream section of the area are excluded from the proposed aquatic reserve. To the north-east, the proposed aquatic reserve is bounded by the proposed Muskuchii hills biodiversity reserve, to which temporary protection status similar to the status of the North Harricana river aquatic reserve was assigned for a period of 4 years beginning on May 7, 2003.