Beneath Boulder County’s scenic landscapes lies a story of shifting continents, ancient seas, and valuable minerals that shaped the region’s history. Join Rick and Becky Lewis, Boulder County volunteers, for a look at how plate tectonics formed the Colorado Mineral Belt. They will share the stories behind three of the county’s most notable mineral deposits: gold at Gold Hill, silver at Caribou, and tungsten below Barker Reservoir. Registration for most programs begins on the 20th of the month before the event. Registration required. Register .tribe-events-c-subscribe-dropdown{display:none;}