The hydrographic slope of the Armitage River is accessible by the junction of a forest road serving the eastern side of Chibougamau Lake; the latter is connected by the North to route 167 which also serves the south side of Waconichi Lake and the Waconichi River.

The surface of the Armitage River is usually frozen from early November to mid-May, however safe ice circulation is generally from mid-November to mid-April.

The Armitage River originates at the mouth of Lake André (length: 1.7 kilometres (1.1 mi); altitude: 409 metres (1,342 ft)) in Dollier Township.

This source is located at: From its source (Lake André), the Armitage River flows over 26.7 kilometres (16.6 mi) generally to the northeast, according to the following segments: The Armitage River flows to the south shore of Girard Bay which is an extension of the Bay of Islands northeast of Chibougamau Lake.

From the mouth of the Armitage River, a peninsula advances in a straight line across the 1.7 kilometres (1.1 mi) to the northeast in the bay to the Point Needle.