In May 1859 the discovery of gold in Gregory Gulch by its namesake, John H. Gregory, brought thousands of prospectors and miners into the area, combing the hills for more gold veins. The Bobtail lode was discovered the following month. Hardrock mining boomed for a few years, but then declined in the mid-1860s as the miners exhausted the shallow parts of the veins that contained free gold, and found that their amalgamation mills could not recover gold from the deeper sulfide ores.