Two mines open pit gold mines in the Black Hills illustrate the differences that can occur when mining an oxide ore body relative to a sulfide ore. The Wharf Mine has mined an oxidized ore body and has averaged about 70,000 ounces of gold per year  since the 1990s. It has a clean environmental record. The second, the Gilt Edge Mine, operated from 1994 to 2001. The mine went bankrupt due to a collapse in gold prices and the overwhelming amount of acid rock drainage (ARD) generated by an exposed sulfide ore body. The site became a US EPA Superfund site and as of the early 2000's contained 160 million gallons of sulfuric acid along with leaks into surrounding streams. Remediation by US EPA contractors has resulted in containing the ARD and reduced the total amount to 30 million gallons as of late 2016. Meanwhile, the surrounding streams have been remediated. The following essay elaborates on the stories of these two mines which are sited about six miles apart.