[citation needed] In 1818, Sir John Ross's expedition made first contact with nomadic Inuktun in the area.

[4] Robert Peary built a support station by a protected harbor at the foot of iconic Mount Dundas in 1892.

USAAF Colonel Bernt Balchen, who built Sondrestrom Air Base, knew Rasmussen and his idea.

Balchen led a flight of two Consolidated PBY Catalina flying boats to Thule on 24 August 1942 and then sent a report advocating an air base to USAAF chief Henry "Hap" Arnold.

However, the 1951 air base site is a few kilometers inland from the original 1946 airstrip and across the bay from the historical Thule settlement, to which it is connected by an ice road.

The joint Danish-American defense area, designated by treaty, also occupies considerable inland territory in addition to the air base itself.

Nonetheless, in summer 1946, the radio and weather station was enhanced with a gravel airstrip and an upper-air (balloon) observatory.

In 1946–1951, the airstrip played an important role in Arctic resupply, aerial mapping, research, and search-and rescue.

In 1949, Denmark joined NATO (North Atlantic Treaty Organization) and abandoned its attempt to remove the United States bases.

By the outbreak of the Korean War next year, the USAF embarked on a global program of base-building in which Thule (at the time) would be considered the crown jewel owing to its location across the Pole from the USSR, as well as its merit of being the northernmost port to be reliably resupplied by ship.

Strategic Air Command (SAC) bombers flying over the Arctic presented less risk of early warning than using bases in the United Kingdom.

A board of Air Force officers headed by Gordon P. Saville made a recommendation to pursue a base at Thule in November 1950.

Thule Air Base was constructed in secret under the code name Operation Blue Jay, but the project was made public in September 1952.

[7] The United States Navy transported the bulk of men, supplies, and equipment from the naval shipyards in Norfolk, Virginia.

On 16 June 1951, the base was accidentally discovered by French cultural anthropologist and geographer Jean Malaurie and his Inuit friend Kutikitsoq, on their way back from the geomagnetic North Pole.

[8] Originally established as a Strategic Air Command installation, Thule would periodically serve as a dispersal base for B-36 Peacemaker and B-47 Stratojet aircraft during the 1950s, as well as providing an ideal site to test the operability and maintainability of these weapon systems in extreme cold weather.

After a two-hour head start, a B-47 would catch up with them at the northeast coastline of Greenland where two would offload fuel to top off the B-47's tanks (the third was an air spare).

[9] Carved into the ice, and powered by a nuclear reactor, PM-2A Camp Century was officially a scientific research base, but in reality was the site of the top secret Project Iceworm.

[citation needed] In 1957 construction began on four Nike Missile sites around the base, and they and their radar systems were operational by the end of 1958.

In 1961, a Ballistic Missile Early Warning System (BMEWS) radar was constructed at "J-Site", 21 km (13 mi) northeast of main base.

[12] There is only a brief period each year in the summer when sea ice thins sufficiently to send supply ships to the base.

[20] It was originally the classified 6594th Test Wing's Operating Location 5 designated by Air Force Systems Command on 15 October 1961: the station was operational on 30 March 1962, with "transportable antenna vans parked in an old Strategic Air Command bomb assembly building.

[26] More than 700 Danish civilians and US military personnel worked under hazardous conditions, the former without protective gear, to clean up the nuclear material.

Kaare Ulbak, chief consultant to the Danish National Institute of Radiation Hygiene, said Denmark had carefully studied the health of the Thule workers and found no evidence of increased mortality or cancer.

After reviewing these files, an investigative reporter from BBC News claimed in May 2007 that the USAF was unable to account for one of the weapons.

[33] Pituffik has a tundra climate (ET) with long, severely cold winters lasting most of the year and short and cool summers.