The Blakiston Line is a biogeographical boundary that separates the flora and fauna of the eastern and western regions of North America. It runs roughly along the eastern edge of the Rocky Mountains and marks a significant transition in species distribution. This line is named after the Canadian naturalist William Blakiston, who studied the differences in wildlife across this divide. Species on the eastern side of the Blakiston Line tend to be more temperate, while those on the western side are often adapted to drier, mountainous environments. The line is important for understanding ecological zones and the impact of geography on biodiversity in North America.