The churn drill was one of the most innovative and important tools for placer prospecting in Alaska. Prospectors used to sink shafts by hand many tens of feet to bedrock, often in frozen ground. Now they could test far more ground far faster and with less effort. From the attached article: "In 2009, miners who were cleaning up an old mining claim near Coldfoot, Alaska, donated a 1920s-era churn drill to the Bureau of Land Management. The drill, rusted and overgrown with willows, might not have