[2] It is located along Highway 11 and the Canadian National Railway, on the namesake Longlac Bay at the northern end of Long Lake.

In 1819, Henley House was destroyed and Long Lake became district headquarters, until it closed in 1821 (when the HBC and NWC merged).

[5] In the 1910s, the Canadian Northern Railway was built along the north end of Long Lake and opened for passenger service in 1915.

[11][12] In 2001, Longlac was amalgamated with the former Townships of Beardmore and Nakina, and the Town of Geraldton, together with previously unorganized areas, into the new municipality of Greenstone.

[13] Railroad traffic from Longlac to Thunder Bay gradually declined, and this section was abandoned in 2005 and the rails were removed in 2010.