Population Migration / Travel
During the height of the gold rush, many cities near the mineral-rich mountain caves experienced a boom in their economies. Later, many of these cities would become ghost towns once all the easy to extract minerals and gems had been mined dry.
Some cities continued to grow by adapting or digging even deeper mines. One such example is the city of Cappleton. The dwarves living here turned to dig deeper into the mountain and expand their trade of manufactured goods.