A miner at heart, Hagerman was not about to be left out of the silver boom hitting the region.
 H.B. Gillespie, a mine owner in the region who had been involved in several major silver strikes, owned the Mollie Gibson mine, near Aspen.
A major silver vein had been discovered in the mine, but Gillespie was convinced that the vein also ran under a number of other, nearby mines.
Seeking capital to purchase these properties before news of the strike got out, Gillespie contacted Hagerman, who agreed to invest heavily in the new company.
In 1890, the Mollie Gibson Mining & Milling Company was organized with Gillespie as manager and Hagerman as president.
The company quickly purchased the Lone Pine, Silver King and Sargent mines and invested heavily in the Emma and other smaller mines.
The company announced its silver strike on December 9, 1890.
The combined Mollie Gibson mine became the richest silver mine in the world until that time.

Still suffering from the effects of tuberculosis, Hagerman moved to New Mexico in 1892.
But he retained his Colorado holdings, and took an active hand in managing his interests there.

The Panic of 1893 and repeal of the Sherman Silver Purchase Act caused the value of silver to collapse.
But the price of gold remained unaffected, and the gold mining industry was still strong.
A major gold strike near Cripple Creek, Colorado, led Hagerman to become involved in gold mining.
A miner at heart, Hagerman was not about to be left out of the silver boom hitting the region.  H.B. Gillespie, a mine owner in the region who had been involved in several major silver strikes, owned the Mollie Gibson mine, near Aspen. A major silver vein had been discovered in the mine, but Gillespie was convinced that the vein also ran under a number of other, nearby mines. Seeking capital to purchase these properties before news of the strike got out, Gillespie contacted Hagerman, who agreed to invest heavily in the new company. In 1890, the Mollie Gibson Mining & Milling Company was organized with Gillespie as manager and Hagerman as president. The company quickly purchased the Lone Pine, Silver King and Sargent mines and invested heavily in the Emma and other smaller mines. The company announced its silver strike on December 9, 1890. The combined Mollie Gibson mine became the richest silver mine in the world until that time.
Still suffering from the effects of tuberculosis, Hagerman moved to New Mexico in 1892. But he retained his Colorado holdings, and took an active hand in managing his interests there.
The Panic of 1893 and repeal of the Sherman Silver Purchase Act caused the value of silver to collapse. But the price of gold remained unaffected, and the gold mining industry was still strong. A major gold strike near Cripple Creek, Colorado, led Hagerman to become involved in gold mining.
J. J. Hagerman