In 1874 gold was discovered on the eastern slope of the Santa Rita Mountains. The area became known as the Greaterville mining district and proved to be one of the richest placer deposits in southern Arizona. Placer deposits consist of a mixture of gold, sand and gravel; to separate the substances, water is required. Generally, water is readily available to wash the mixture of sand, gravel, and gold. However, the arroyos of the Santa Rita Mountains are dry. Miners were required to haul the sacks of dirt to the few running streams in the area. Sometimes they would carry packed water, in canvas and goatskin bags, on the backs of burros to their claims. By 1886, much of the rich deposits that were worth such an effort were worked out and many miners gave up and moved on.