“INITIATIVE 137 was a response to the abysmal track record of open pit cyanide leach mining in Montana, as exemplified by cleanup fiascos at the Golden Sunlight, Zortman/Landusky, and Kendall mines and the Montana Department of Environmental Quality’s failure to adequately regulate such mines as required by state law.”
http://www.savethesantacruzaquifer.info/Chemicals.htm