The R1027 bridge spans the Allard River about 10 kilometres (6.2 mi) South of its confluence with the Lake Matagami.

The Allard River originates from a head lake (length: 0.6 kilometres (0.37 mi); elevation: 283 metres (928 ft)) on the territory of Eeyou Istchee Baie-James (Municipality), a little North of the boundary of the administrative region Abitibi-Temiscamingue.

The Allard River empties onto the west shore of Lake Matagami, across from "Île aux Brochets".

The course of the Allard River runs North for about a hundred kilometers to the West shore of Lake Matagami.

The Algonquins designate this watercourse "Sagackweia Sibi", meaning "river of the great valley with hay".