This report describes the general, structural and economic geologies of the eastern Lac des Milles Lacs area, District of Thunder Bay. This area is about 300 square miles. The centre of the report-area is about 65 miles northwest of the cities of Fort William and Port Arthur.

This report contains an inventory of regional engineering terrain conditions in the Lac des Mille Lacs area, districts of Rainy River and Thunder Bay. The information was obtained from aerial photographs checked with published and unpublished literature documenting previous field visits and observations. In fall 1978, roads in the area were traversed and observed terrain conditions recorded as further verification of the office studies. The report describes the geological setting and the engineering terrain units of the area, including organic, bedrock, glaciolacustrine, moraine, glaciofluvial and alluvial.

1919/28 cumulation includes material previously issued in the 1919/20-1935/36 issues and also material not published separately for 1927/28. 1929/39 cumulation includes material previously issued in the 1929/30-1935/36 issues and also material for 1937-39 not published separately.