Question: What do Hedley Mascot Mine and Ruth Mine have in common?
Related documents: [0]  [DOC] The Hedley Mascot Mine was a gold mine in Hedley, British Columbia, Canada. Gold was first discovered in the Nickel Plate Mountain area in 1897 and several small mines were developed over the years. The Hedley Mascot Mine operated between 1936 and 1949 and was one of the most unusual mining operations in the world, being built entirely on the side of a mountain, 5,000 feet above the town of Hedley or seven thousand feet above sea level. In the 1990s, the British Columbia government was going to burn the site down because it posed a safety risk, but the Minister of Tourism at the time intervened and, in 1995, steps were taken to preserve the site as a Provincial Heritage resource. [END] 
[1]  [DOC] 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. [END] 
Answer: 
gold mine
gold mine