Carte Generale des Decouvertes de l'Amiral de Fonte, . . (Explorers)

An interesting map of the NW Coast of America and the NE Coast of Asia, based upon Jefferys map of 1768.
Prior to Cook's 1st Voyage, the English, French and Russians were actively debating the cartography of the region in the North Pacific between Asia and North America. The Russian explorations of the first half of the 18th Century, including those by Behring, Tchirikow and others, had been reported by JN de L'Isle, who had worked with the Russians and was privy to their latest discoveries.
The mythical voyages of De Fuca, d'Aguilar and De Font were still very much in evidence in contemporary cartography, as were concepts of a NW Passage, the Sea of the West, River of the West and other vestiges of 16th and 17th Century conjectural/mythical cartography.
Following the publication by Buache of his maps on the region, the debate between the French and English was quite fertile, so much so that Diderot dedicated most of his 10 map supplement to the region.

This map shows the Jefferys model, including a wide De Fuca based River from Puget Sound to the Atlantic over Hudson's Bay, several significant rivers flowing from the Pacific to the middle of North America, and Jesuit based water passages from the Pacific to the Arctic Seas. A marvellous approximation of Alaskan Archipelago is shown, along with the Russian discoveries.