This volume is a pioneering excursion into the documentary history of a region of northern Ontario. Previously published original documents on the history of the Thunder Bay area have been of two kinds: accounts of the fur trade before 1821, and evidence supporting rival claims in the boundary disputes of the 1870s and 1880s. Although this collection does not include some illustrative material on these topics, its main purpose is to shed light upon other aspects of northern development, including the best-known and most pervasive problem-isolation from the rest of British North America. This volume deals with events up to 1892, considerably later than any of the other volumes in the Ontario Series. The documents tell the story of the silver mines-from the first rumours of wealth, through the excitement of the Silver Islet era, to the closing down of the mines in the early 1890s-and place the era of transcontinental railway building as part of local rather than national history. The documents also treat the development of numerous communities created through mining activity and railway building, showing how precariously they were based, how jealous they were of rival towns, and how anxious for the favours they might receive from government or company decisions. This collection should provide a basis for continuing research into northwestern Ontario history.