Gold and silver were discovered in 1907, four miles west along the Ophir Grade to Washoe Valley. Selby Mining Co. built the first mill, followed by the Jumbo Saloon, Mineral Barber Shop, Hotel Jumbo, and, until 1910, a U.S. Post Office. The Jumbo Miner, the camp newspaper, published for three months and twenty-one days during 1908. The Washington - Nevada Co. built and operated a ten stamp mill from 1915 to 1921, marking the end of large production at Jumbo.