Question: Which one is closer to Yellowknife, Outpost Island Mine or Colomac Mine? 

Context paragraphs:
Discovery Mine: The Discovery Mine was a gold mine 81 kilometers northeast (approx bearing of 15 degrees) of Yellowknife, Northwest Territories that operated between 1950 and 1969.  Gold was discovered here by Alfred Giauque in 1944.  A complete townsite, on Giauque Lake, was established by the company to house workers and their families.  The mine produced one million troy ounces (31,000 kg) of gold from one million tons of ore.  The abandoned townsite, not accessible by road, was demolished in 2005.

Colomac Mine: The Colomac Mine was a privately owned and operated open pit gold mine located 220 km northwest of Yellowknife in the Northwest Territories in Canada .  The Colomac mine operated between 1990–1992, and 1994–1997.  It was operated by Neptune Resources Limited that had little success in making a profit during its operation.  In 1994, the mine had reopened under Royal Oak Mines Inc.  Both Neptune Resources and Royal Oak Mines where both owned and operated by Peggy Witte.  Due to low gold prices and high cost of mining, Royal Oak Mines was forced into bankruptcy.  The Federal Government of Canada became owners of the mine, along with the related environmental issues.  A major cleanup effort is under way to prevent the mine from polluting the environment, but this might be too late at this stage.  This mine is now owned and controlled by the Indigenous and Northern Affairs department of the Federal government, while Public Works and Government services is the current contracting authority.

Gag Island mine: The Gag Island mine is a large mine in the east of Indonesia in Sulawesi.  Gag Island represents one of the largest nickel reserve in Indonesia having estimated reserves of 240 million tonnes of ore grading 1.35% nickel.  The 240 million tonnes of ore contains 3.24 million tonnes of nickel metal.

Outpost Island Mine: The Outpost Island Mine was a gold and tungsten producer 94 kilometres southeast of Yellowknife, Northwest Territories on an island of Great Slave Lake.  Gold was discovered here in 1935 by prospectors, and some development was undertaken in 1936-1938.  Tungsten ores became valuable during World War II, so the owners (Slave Lake Gold Mines Limited) investigated the tungsten possibilities of the mine.  It produced small amounts of gold, copper, and tungsten during 1941-1942, and then again in 1951-1952 during the Korean War.  It was a small deposit and was not considered economic because of unpredictable tungsten market prices in the 1950s.

Ruth Mine: The Ruth Mine was a small gold producer about 65 km (40 miles) east of Yellowknife, Northwest Territories.  It operated briefly during 1942 and then again in 1959, extracting only 550 troy ounces (17 kg) of gold thus far.  The old mine is today (2012) significant as one of the last intact abandoned mining properties from the 1940s period in the Northwest Territories, although the site was scheduled to be remediated by the federal government.

Marcopper mining disaster: The Marcopper Mining Disaster occurred on March 24, 1996, on the Philippine island of Marinduque, a province of the Philippines located in the Mimaropa region.  It remains one of the largest mining disasters in Philippine history.  A fracture in the drainage tunnel of a large pit containing leftover mine tailings led to a discharge of toxic mine waste into the Makulapnit-Boac river system and caused flash floods in areas along the river.  One village, Barangay Hinapulan, was buried in six feet of muddy floodwater, causing the displacement of 400 families.  Twenty other villages had to be evacuated.  Drinking water was contaminated killing fish and freshwater shrimp.  Large animals such as cows, pigs and sheep were overcome and killed.  The flooding caused the destruction of crops and irrigation channels.  Following the disaster, the Boac River was declared unusable.

Lontor: Lontor is an island in the Banda Islands, Indonesia.  The Dutch established friendly relations and a trading outpost in 1599, but in 1609 the local Chiefs rebelled, killing 30 Netherlanders.  This resulted in a brutal campaign against the people of Lontor by the Dutch in retaliation for not obeying the rules of the Dutch trade monopolies.  By 1619, the Banda islands population had been reduced from 15,000 to less than one thousand.  The English had an outpost there in the 1600s, but the Dutch maintained control in this area and the British were entirely expelled by the Dutch by 1684.  The Dutch maintained control of the island largely because of its ample crops of nutmeg.

Dolphin mine: The Dolphin mine is a large open pit and underground mine located in the Bass Strait on King Island, Tasmania, Australia.  Dolphin represents one of the largest tungsten reserves in Australia having estimated reserves of 2.7 million tonnes of ore grading 1.04% tungsten.

Colomac Airport: Colomac Airport (TC LID: CFY8) , was located near Colomac Mine in the Northwest Territories, Canada where caribou may be found on the runway.  Prior permission was required to land except in the case of an emergency.

Simberi mine: The Simberi mine is one of the largest gold mines in Papua New Guinea and in the world.  The mine is located in the north of the country on Simberi Island, New Ireland Province.  The mine, owned by St Barbara Limited, has estimated reserves of 3.3 million oz of gold.

Supporting paragraphs: Outpost Island Mine Colomac Mine
Answer: Outpost Island Mine