According to the Canadian Geographical Names Database, part of Natural Resources Canada, it is located in Lac-Jérôme, in the extreme western part of the Minganie Regional County Municipality[1] but is in the Sept-Rivières Regional County Municipality.
The substation was built in the 1970s along a series of 735kV transmission lines connecting to the Churchill Falls Generating Station and was the location of a failure that caused a major blackout throughout the province in September 1977.
[3][4] The second failure on November 26, 1988, was initially falsely attributed by Hydro Quebec to the magnitude 5.9 1988 Saguenay earthquake.
[3][5] In the mid-2010s additional transmission lines were constructed, connecting the substation to the Romaine-3 and Romaine-4 Generating Stations on the Romaine River in the Côte-Nord region.
Poste Montagnais has pretty much uniform precipitation throughout the year with slightly more in the summer months.