The authors show that meteorologic data and weather information recorded at the HBC trading posts over two centuries provide the largest and longest consecutive series available anywhere in North America, one that can help us understand the mechanisms and amount of climate change. They demonstrate that Hudson Bay is the second largest site of new bird species named by Linnaeus and reproduce some of George Edwards' colour paintings of these new species. Six informative appendices reveal how the invaluable HBC archives were transferred from London, England, to Winnipeg, correct previous misinterpretations of the collaboration and relative contributions of Thomas Hutchins and Andrew Graham, use two centuries of HBC fur returns to demonstrate the ten-year hare and lynx cycles, tell how the swan trade almost extirpated the Trumpeter Swan, explain how the Canada Goose got its name before there was a Canada, and offer an extensive list of eighteenth-century Cree names for birds, mammals, and fish. Informative tables list the eighteenth-century surgeons at York Factory and give names and dates for the annual supply ships.