Initial assays were promising, but it wasn't until 1901, when the partners struck a rich vein of silver and lead. They estimated the find at $1 to 1.5 million. One sample assayed at 11,229 ounces of silver per ton, an incredibly rich ore. They erected new buildings including an ore bin, a wood shed, and others. They persuaded the county to improve the road to the mine. They arranged contracts with smelters at Perth-Amboy in New Jersey and Puget Sound Reduction Company in Everett, Washington, to process their ore.
By the end of 1903, the Hercules was making a profit of $40,000 per month. It had tunnels at three levels, 1,000 feet below the surface. The company installed a generating station and were using air drills. There was also a sawmill and a tramway and several offices. Harry Day bought several adjoining claims that followed the vein. In 1905, Day built a state-of-the-art mill that wasted less ore than other mills.
During this time Harry Day was active politically. He worked hard to oppose lowering tariffs on imported ores, which the mine owners felt would hurt their businesses. He also worked on taxation laws which taxed mines based on net profits rather than property value. This reduced the amount of taxes paid.
In 1906, the mine began to see favorable assays on zinc. Production was held off until railroad transportation prices improved. A financial panic in 1907 reduced production in all the Idaho mines and some closed for good. The Hercules had enough money though to acquire a few adjoining properties at a cheap price. During this time technological improvements were made in the mine, mainly outfitting with electrical tools and power and improved explosives. The mill burnt down, but a new one was quickly built in Wallace.
