Yogo Sapphires

The panel blames synthetic stones for the 1929 closing; the record points to water. The English Mine, owned in London and working the Yogo dike from 1899, was so damaged by floods on July 26, 1923 that it never fully recovered, and it failed in 1929 amid hard times after yielding more than sixteen million carats of rough sapphire. The stones made their name in a cigar box: Jake Hoover sent his blue pebbles to an assay office, which mailed them to Tiffany's in New York, where George Kunz judged them the finest gems yet found in the country.

What the plaque says

Yogo Sapphires Rumors of gold in the Little Belt Mountains was enough to cause a stampede by hundreds of miners into the Pig-eye Basin and Yogo Gulch southwest of here in the spring of 1879. Although the placer mines soon played out, there was still enough gold in the area to hold the interest of prospectors and settlers for years. In 1895, Jake Hoover and Frank Hobson established a small placer mine on Yogo Gulch. When they cleaned their sluice boxes, they didn't find much gold, but they did find a lot of small blue glassy pebbles, which they threw away. It wasn't until later that they discovered the stones were high grade, gem-quality sapphires. Yogo sapphires have a distinctive deep blue cast to them that is found no where else in the world. Commercial mining of the gems began around 1900 and continued until about 1929 when synthetic sapphires became readily available, causing the Montana mines to close down. Since then, sapphire mining has only been sporadic. When combined with Montana gold, Yogo sapphires make a mighty pretty and unique combination for rings, cuff links, pins and similar fancy doo-dads.

Where it stands

More markers nearby

• The Nez Perce Conflict of 1877 — 20 mi
• Lewistown Army Airfield — 20 mi
• The Judith Basin Country — 20 mi