Unlike the early days of the California Gold Rush, very few large nuggets were ever found in the Colorado diggings. A gold pan was adequate for finding "pay dirt", but to produce more than a small amount of gold, sluice boxes were built to separate the gold dust from the gravel. They were built on site from the material that was at hand and placed in the river current. The old sluice boxes were lined with raised obstructions that were placed in a vertical position to the flow of the current and when the gold-laden gravel was shoveled into the upper end of the sluice, the flow of water carried the material down the length of the box. The gravel was carried down the entire length of the sluice and then discharged, but the heavier flakes of gold settled and became trapped. Signs of placer mining up and down along the Arkansas river near Granite and the surrounding areas are in evidence by the many heaps of glacially rounded granite boulders, rocks that were once buried in the glacial gravel deposits.