Everything in Placer County history leads to gold, from its name—the Spanish term for gold-bearing gravel—to the mining camps that sprouted overnight in its rugged river canyons. Ecstatic cries of "Gold on the American River!" in 1848 launched the largest voluntary migration in the history of the world. As claims "panned out," thousands of miners swarmed like locusts between the rough-and-tumble mining camps, from the crest of the Sierra Nevada to the Sacramento Valley. Some camps disappeared along with the easy placer gold; others found new methods to extract gold deposited deep in quartz veins or underground and developed into stable towns that still stand. Sometimes washing whole hillsides into rivers, hydraulic mining was outlawed in the 1880s, but the colorful characters and tall tales of the Gold Rush live on.