Rainy Lake lies on the boundary waters west of Lake Superior, between present-day Canada and the United States. In Rainy Lake House, Theodore Catton uses the chance encounter in 1823, at the Hudson's Bay Company (HBC) post of the same name, of three men who were very different but who each left a written record of that encounter and of his life.

The first is Dr. John McLoughlin (1784–1857) a former North West Company agent and factor and, with the amalgamation of the North West Company and HBC in 1821, the chief factor at the post. McLoughlin was also a surgeon raised and trained in Quebec who spent his life as a trader and factor and ended his career as chief factor and superintendent of the Columbia (River) District. The second man is Stephen H. Long (1784–1864), an American explorer and topographical engineer for the U.S. Army Corps of Topographical Engineers, who made several journeys of exploration up through the Great Lakes. The third is John Tanner (1780–1846), who at the age of nine was kidnapped from his family's homestead on the Ohio River in present-day Kentucky. He lived with the Ojibwa and Ottawa peoples for most of his life. Each of these men left us a documentary record through diaries, journals, letters, and field logs. Tanner also wrote a narrative account of his life.

Catton frames the book around an episode that took place at Rainy Lake House when Tanner was attempting to bring his children, whom he had not seen for some years, back to Mackinac. As the epicenter of the book, Tanner's desire to take his children from their mother and their homeland after years of separation is a rather tawdry episode and one filled with as much supposition as fact.

In the book, Catton uses the documentary evidence to provide a bibliographical narrative of these three men's lives to and through their meeting in 1823. This is a very un-nuanced discussion of the time period and of each man's position. The varied documentary evidence is taken at face value and laid out as an unbiased description of the world these men occupied. In the late eighteenth century, the boundary waters were the transshipment point for furs from farther west to Montreal. It was also a region into which the HBC, previously situated only on Hudson Bay, was moving. Additionally, American explorers and some fur traders were entering the region. Thus, events revolve around the fur trade and the impact of a commercial trade on indigenous communities.

Interesting as the literary construction of the book is, it is very disappointing and perhaps even dangerous in its presentation of the fur trading world. The author buttresses his narrative from the source material using outdated sources along with a veneer of some more recently published works. The result is that the book perpetuates some very old tropes that revisionist history has shown to be false. The first of these is its setting the stage as one between the “savage” and “civilized” worlds. Equally problematic is his description of the fur trade. Here Catton regurgitates an old and completely inaccurate description of the trading environment in the Canadian fur trade at this time. In Catton's description, indigenous traders gave away furs in their desire to obtain alcohol. He uses a few episodes from Tanner's narrative from his early years, where a teenage boy describes the desire for alcohol by his mother and those in the trading party as so dominant that being drunk was the objective of the trade. Catton also asserts that the traders were complicit with this by sending vast quantities of liquor to the posts. Revisionist work, to which I have contributed, has shown that in comparison to Americans and English, the indigenous community in subarctic Canada consumed very little alcohol. Building on the work of Arthur Ray, we know that indigenous traders were equal and powerful players in the exchange of furs for European commodities. Indigenous traders not only bargained to maximize their part of the trading surplus, but also determined what commodities they would and would not buy with their furs. Also incorrectly, Catton talks about the high markups on European trinkets traded to indigenous traders. Again, the work of the last twenty years has shown that shipping commodities to the frontier was costly and the markups low, especially on low value-to-weight commodities.

The subtitle of the book, Twilight of Empire on the Northern Frontier, is never explained. The reader has no sense of what frontier, whose empire, or what twilight. Rather, one is left with an inaccurate and simplistic account of a fur trading world that was complex and beneficial for many for more than a century. Unfortunately, trade based on a renewable but depletable resource could not be the basis of sustained economic growth.