The Climax mine on Fremont Pass is a different mining story than silver

When people think of mining in Lake County, they picture Leadville’s silver. But the county has a second, very different mining story up on Fremont Pass: the Climax mine. Instead of silver or gold, Climax produces molybdenum, a metal used to harden steel.

The geology and the history both stand apart. The Climax deposit sits high near Fremont Pass, on the line between Lake and Summit counties, and large-scale production began around the World War I era when industry started using molybdenum in steel. That timing matters: Climax rose as the old silver camps were fading, so it kept a mining economy alive here long after the boom days.

The Colorado Geological Survey treats Climax and Leadville as the county’s two major mining districts. For a newcomer, that helps explain the modern landscape. The drive north over Fremont Pass passes a working industrial site, not just historic ruins, and mining is still part of this area’s present, not only its past.

Mining activity, ownership, and public access change over time, so do not assume current conditions from history. For the geology and history of the Climax district, start with the Colorado Geological Survey’s pages on Colorado metals and historic mining districts.