A variety of blue sapphire found in the Yogo Gulch area of Judith Basin County, Montana. People panning for gold in the mid-1800s noticed the "blue pebbles" and disregarded them because they were not recognized as sapphires, and there was no market for gem rough in Montana at that time. Their value was realized after a local rancher sent a small box of them to an assay office, who forwarded them to Tiffany's in New York, who sent the rancher a surprising check. Some early mining efforts in the area were profitable, and this triggered the discovery and sporadic production of sapphires in other parts of Montana. Today, most sapphires found in Montana are through the efforts of hobby miners working placer deposits. A few locations are open to the public on a fee mining basis.