Question: How long is the highway Whitehorse/Cousins Airport was built to support as of 2012?

full_context: Document 1: Erik Nielsen Whitehorse International Airport: Erik Nielsen Whitehorse International Airport (IATA: YXY, ICAO: CYXY) is located in Whitehorse, Yukon, Canada. It is part of the National Airports System, and is owned and operated by the Government of Yukon. The airport was renamed in honour of longtime Yukon Member of Parliament Erik Nielsen on December 15, 2008. The terminal handled 294,000 passengers in 2012, representing a 94% increase in passenger traffic since 2002. Air North is based in Whitehorse.
Document 2: Canol pipeline: The Canol pipeline was built to carry crude oil from Norman Wells, Northwest Territories, in Canada to Alaska, USA, during World War II. The routing was to Johnson Crossing and then along the Alaska highway to Whitehorse, Yukon, where a refinery was built.
Document 3: Alaska Highway: The Alaska Highway (also known as the Alaskan Highway, Alaska-Canadian Highway, or ALCAN Highway) was constructed during World War II for the purpose of connecting the contiguous United States to Alaska across Canada. It begins at the junction with several Canadian highways in Dawson Creek, British Columbia, and runs to Delta Junction, Alaska, via Whitehorse, Yukon. Completed in 1942 at a length of approximately 2700 km , as of 2012 it is 2232 km long. The difference in distance is due to constant reconstruction of the highway, which has rerouted and straightened out numerous sections. The highway was opened to the public in 1948. Legendary over many decades for being a rough, challenging drive, the highway is now paved over its entire length.
Document 4: Pine Lake Aerodrome: Pine Lake Aerodrome formerly Daughney Aerodrome (TC LID: CFY5) is a registered aerodrome located near the Alaska Highway, 63 NM west of Watson Lake, Yukon, Canada.
Document 5: Whitehorse/Cousins Airport: Whitehorse/Cousins Airport (TC LID: CFP8) is an unpaved airstrip located in Whitehorse, Yukon, Canada, 8 NM northwest of the city centre between the Alaska Highway and the Yukon River. This airport has no services at all, and is used primarily as an emergency landing area and for local pilot training. Vehicles enter via Cousins Access Road. The airport was built to support the Alaska Highway construction and the Northwest Staging Route.
Document 6: Braeburn Airport: Braeburn Airport, also known as the Cinnamon Bun Airstrip, (TC LID: CEK2) in the Yukon, Canada, is adjacent to the Klondike Highway between Whitehorse and Carmacks. It is next to Braeburn Lodge (famous for its oversized cinnamon buns and sandwiches) and near Braeburn Lake. It receives no maintenance and pilots are advised to use caution as there are numerous holes in the runway caused by gophers.
Document 7: Going-to-the-Sun Road: Going-to-the-Sun Road is a scenic mountain road in the Rocky Mountains of the western United States, in Glacier National Park in Montana. The Sun Road, as it is sometimes abbreviated in National Park Service documents, is the only road that traverses the park crossing the Continental Divide through Logan Pass at an elevation of 6,646 feet (2,026 m), which is the highest point on the road. Construction began in 1921 and was completed in 1932 with formal dedication in the following summer on July 15, 1933. The road is the first to have been registered in all of the following categories: National Historic Place, National Historic Landmark and Historic Civil Engineering Landmark. The length of the road is approximately 50 miles (80 km) and spans the width of the park between the east and west entrance stations. The National Historic Landmark Nomination records a slightly shorter distance of 48.7 miles which is measured from the first main intersection just outside the park's west entrance to Divide Creek in St. Mary on the east side of the park.
Document 8: Robert Campbell Highway: Yukon Highway 4, also known as the Robert Campbell Highway or Campbell Highway, is a road between Watson Lake, Yukon on the Alaska Highway to Carmacks, Yukon on the Klondike Highway. It is 583 km long and mostly gravel-surfaced. It serves the communities of Faro and Ross River and intersects the Canol Road near Ross River. The highway is named for Robert Campbell, a nineteenth century Hudson's Bay Company fur trader and explorer.
Document 9: Dalton Highway: The James W. Dalton Highway, usually referred to as the Dalton Highway (and signed as Alaska Route 11), is a 414 mi road in Alaska. It begins at the Elliott Highway, north of Fairbanks, and ends at Deadhorse near the Arctic Ocean and the Prudhoe Bay oil fields. Once called the North Slope Haul Road (a name by which it is still sometimes known), it was built as a supply road to support the Trans-Alaska Pipeline System in 1974. It is named after James Dalton, a lifelong Alaskan and an engineer who supervised construction of the Distant Early Warning Line in Alaska and, as an expert in Arctic engineering, served as a consultant in early oil exploration in northern Alaska. It is also the subject of the second episode of "America's Toughest Jobs" and the first episode of the BBC's "World's Most Dangerous Roads".
Document 10: Northwest Staging Route: The Northwest Staging Route was a series of airstrips, airport and radio ranging stations built in Alberta, British Columbia, the Yukon and Alaska during World War II. It extended into the Soviet Union as the ALSIB (ALaska-SIBerian air road).
Document 11: Ross River, Yukon: Ross River is an unincorporated community in Yukon, Canada. It lies at the junction of the Ross River and the Pelly River, along the Canol Road, not far from the Campbell Highway. Primary access to the Campbell Highway is via a nine-mile access road. Formerly it was accessed along a six-mile Canol Road section that is no longer maintained. It is serviced by Ross River Airport, used mainly for charter and scheduled flights to and from Whitehorse and Watson Lake.
Document 12: Erik Nielsen Whitehorse International Airport: Erik Nielsen Whitehorse International Airport (IATA: YXY, ICAO: CYXY) is located in Whitehorse, Yukon, Canada. It is part of the National Airports System, and is owned and operated by the Government of Yukon. The airport was renamed in honour of longtime Yukon Member of Parliament Erik Nielsen on December 15, 2008. The terminal handled 294,000 passengers in 2012, representing a 94% increase in passenger traffic since 2002. Air North is based in Whitehorse.
Document 13: Alaskan Way Viaduct: The Alaskan Way Viaduct is an elevated highway in Seattle, Washington built in three phases from 1949 through 1953 and opened on April 4, 1953. It features a double-decked elevated section of State Route 99 that runs along the Elliott Bay waterfront in the industrial district and downtown of Seattle. It is the smaller of the two major north–south traffic corridors through Seattle (the other being Interstate 5), carrying up to 110,000 vehicles per day. The viaduct runs above the surface street, Alaskan Way, from S. Nevada Street in the south to the entrance of Belltown's Battery Street Tunnel in the north, following previously existing railroad lines.
Document 14: Air North: Air North Charter and Training Ltd., operating as Air North, Yukon's Airline is a Canadian airline based in Whitehorse, Yukon. It operates scheduled passenger and cargo flights, charter flights, and ground handling services throughout the Yukon, with regular flights to the Northwest Territories, Alaska, British Columbia, Alberta, and Ontario. Its main base is Erik Nielsen Whitehorse International Airport.
Document 15: Prairie Creek Airport: Prairie Creek Airport (TC LID: CBH4) , is located next to Prairie Creek, Northwest Territories, Canada. Prior permission is required to land except in the case of an emergency. The airport is closed from the 1 September until the 30 April.
ground_truth: 2232 km