This scholarly history of the Hudsons' Bay Company focuses on the company in the years 1821-1843, immediately after its merger with the North West Company. Richard Mackie's thorough research attends closely to journals and correspondence of HBC employees. George Simpson, appointed Governor of the Columbia division by the company's London-based directors, is featured. Simpson was a prototype for the CEOs we now take for granted: ruthless, arrogant, at times heartless, he rationalized company operations, reduced labor costs, developed new products and markets, closed unprofitable divisions, and so on. Mackie takes a benign, at times almost adoring, view of Simpson's actions. The book becomes a paean to the "great men" of the HBC. It is more about Simpson and his fellows than about "the fur trade." The book is diligently researched, and noteworthy for Eric Leinberger's splendid cartography. It is written in clear, straightforward prose. Lacking from the book -- and here's where it loses marks for me -- is any reflection on what the HBC's actions during the early part of the nineteenth century mean now, at the end of the twentieth century. Also missing is any sustained attention to how the HBC's expansion in this area affected the Native populations. This is capital "H" history. Trading Beyond the Mountains will appeal to those interested in "Canada's first corporate merger."