Winnipeg James Armstrong Richardson International Airport Airport is the only commercial international airport within the province as the other airports of entry serve domestic flights and general aviation only. The airport is operated by the Winnipeg Airport Authority as part of Transport Canada's National Airports System and is one of eight Canadian airports that has US Border Pre-clearance facilities. Winnipeg's relatively isolated geographical location in relation to other major population centres makes Winnipeg International Airport the primary airport for a very large area. As such, it is used as a gateway not only to all of Manitoba, but large parts of neighbouring provinces and territories (Saskatchewan,
Winnipeg of the Red River Valley, a flood plain with an extremely flat topography. It is on the eastern edge of the Canadian Prairies in Western Canada and is known as the "Gateway to the West". Winnipeg is bordered by tallgrass prairie to the west and south and the aspen parkland to the northeast, although most of the native prairie grasses have been removed for agriculture and urbanization. It is relatively close to many large Canadian Shield lakes and parks, as well as Lake Winnipeg (the Earth's 11th largest freshwater lake). Winnipeg has North America's largest extant mature urban elm forest.