Yogo Gulch is south of Hwy.. 87 between Windham and Utica in the Judith Basin. This is where the Montana sapphire bonanza was started. Jake Hoover, a friend of cowboy artist Charles Russell, made one of the earliest discoveries of Yogo sapphires. Looking for gold, he found the blue pebbles in the gravels of Yogo Creek in 1896. After sending a few samples off to Tiffany’s in New York he was surprised to receive a check for $17,000. The Yogo mines attracted wide attention and capital. The U.S. Geological Survey termed the location “America’s most important gem location.”
The mining operation has had its up and downs through various owners through the years. The mining operations have been streamlined with new technology and about $40 million worth of the sapphires are mined annually. Yogo sapphires are admired for their ability to retain their amazing brilliance under all forms of light. They are formed very slowly, over 50 million years, allowing impurities to be purged through intense heat and pressure. Sapphires come in nearly all colors except red. Blue is of course the most common and desirable color. Yogo Gulch’s signature “Cornflower Blue” sapphire is known throughout the world and was adopted as Montana’s state gemstone in 1969.
Another well known sapphire mining area in Montana is located near Philipsburg, at Gem Mountain, where Montana Sapphires are found. Montana Sapphire is also legendary for the spectacular array of colors, clarity and brilliance. Some areas around Gem Mountain are open to the public. The Sapphire Gallery in Philipsburg is an excellent source for information about Gem Mountain.