Teaching geology and mining brings a new dimension to knowing Summit County
By Dave Miller
School Programs Director, Keystone Science School
In Summit County, it's hard not to be impressed by the sight of the majestic Rocky Mountains. At KSS, we're proud to call these mountains ‘our place' and strive to honor it by teaching our students about its natural and human history. What better focus for this goal than the study of our local geology and rich mining history?
Generally speaking, geology is the study of rocks. Rocks can be broken into three basic types: igneous, metamorphic and sedimentary. Igneous rock is formed from cooling lava or magma, metamorphic rock is existing rock transformed deep in the earth by heat and pressure, and sedimentary rock is formed through the fusing of sediments by weathering and erosion. In Summit County, all three basic rock types exist, but the majority is igneous and metamorphic.
It can be tough to tell the difference between igneous and metamorphic rocks at first, but a good way to start is to take a look at the size of the crystals that form them. Igneous rocks typically have larger crystals because they've had a chance to cool slowly under the earth's surface. Metamorphic rocks look much denser, and sometimes have folds or curves which make them look like a layered cake, due to heat and pressure which has chemically altered and bended the rock. The next time you're out on a trail, pick up a few medium-sized rocks and see if you can tell which kind they are.
Valuable minerals, such as gold and silver, sometimes make up part of the sediment that makes up rocks. Weathering, erosion, and mountain-building episodes bring the rocks, with their veins of gold and silver, to the Earth's surface where they can be extracted. Summit County became famous in 1859 when gold was discovered here. Miners flocked to this area to try their luck at finding nuggets and flakes through placer mining, or the extraction of minerals from loose rock and sand. Many of these techniques involved water: hydraulic mining, for example, was a method in which high-pressure jets of water were directed against hillsides, flushing dirt and rock into large sluice boxes that helped filter out the gold (you can still see evidence of this practice in what look like avalanche chutes on exposed areas of local hillsides). Other methods were panning — which you can still do today at Breckenridge's Country Boy mine — and dredging, in which large machines collected and combed through the gravel in local riverbeds.
Hike just about anywhere in Summit County and you'll probably come across some remnants of prospecting and mining. To the uninformed eye, they might look simply like old abandoned buildings and tools, but they hold important clues about the history of mining (and the lives of miners) in Summit County. Never enter a mine, and never take anything from a mining site — these historical sites are part of what makes Summit County unique.
If you'd like to learn more, check out the new Breckenridge Open Space interpretive trail on Iowa Hill that guides you through a hydraulic placer mine. Along the trail you can learn about the processes involved and see firsthand the methods and tools that were used. Another area to explore is Peru Gulch in Keystone, which was home to several mines, or the historic town of Montezuma (which was once larger than the town of Breckenridge!). The more you explore and learn about our county's rich history and geological diversity, the more you'll develop your own “sense of place.”
Dave Miller is the school programs director at Keystone Science School. He can be reached at dmiller@keystone.org. To learn more about Keystone Science School, call (970) 468-2098 or visit www.keystonescienceschool.org.
