Eighty years of mining operations on Fremont Pass disturbed more than five square miles of land and altered the course of a stream. As of 2009, Climax Molybdenum Company had spent nearly $50 million on land reclamation and water treatment. Not a dime came from tax dollars.
Land reclamation at 11,000 feet above sea level, where the growing season is about 32 days long, isn't easy. The first step, after the tailings (waste rock) are graded to a final contour, involves spreading crushed limestone on the tailings to neutralize their acidity. Then about four to eight inches of topsoil are added.
That topsoil is produced in the world's highest compost piles from sewage sludge ("biosolids") and wood chips, a mix that decomposes into garden-quality soil with the help of air pumped into the piles. Summit County's biosolids are composted here, as well as biosolids from several other counties and municipalities. Mountain communities and the mine both benefit from this award-winning program: local governments get cost-effective waste management, and Climax gets the raw materials it needs for land reclamation.
The final step in the process is seeding the land with "Climax Mix," a combination of grasses and perennials proven to grow at high-altitude during more than four decades of experimentation. Native
trees like Colorado blue spruce and Engelmann spruce are also planted.