River of the West
Interesting and detailed map of North America, showing the recent discoveries of Cook and other explorers on the west coast of North America, but pre-dating the circumnavigation of Vancouver Island.
Quivira is shown, as is New Albion and Teguayo in the west. Texas is named. The shape of Alaska reflects the discoveries of Cook and other explorers in the last quarter of the 18th Century.
The most salient feature is the mythical River of the West, extending from the "Oregan River" and the area near the Headwaters of the Mississippi River to the Straits of Juan De Fuca, although the last portion of the river is shown with 2 tentative dashed lines.