At the height of the Gondo gold rush in 1894, the Paris-based ''Société des Mines d'Or de Gondo SA'' took over the plant. At that time up to 500 men worked in the valley. With his announcement that he had found a "new California", the director was able to raise 5 million
francs in capital and hire English specialists. In 1893 the general manager of the mine Alcide Froment wrote: {{Blockquote New
smelting plants were built. The
stamp mills and stone mills were powered by water power and electricity. Miners dug for gold in the rugged rock faces and tunnels. The ore was transported to the bottom of the valley with an invention that was revolutionary at the time, the cable car. The gold deposits in the Zwischbergental were mined at altitudes of 1200 m to 1600 m. Mining took place in approximately 50 opencast mines and in 40 tunnels. The gold content could vary from a few grams to 30 grams per ton of ore. In the tunnels, which drop steeply into the Earth's interior and are named
Silzaly, Bruno, Fumée, Fontaine, Julie, Maffiola, Rona, Camozetta, Alcide and
Minna and
Vinasque, the workers toiled in 12-hour shifts for a meager wage, while the operators, in anticipation of rich profits, indulged in luxury and well-being. It soon turned out, however, that the gold extraction was not worthwhile. In the period from March 1, 1894, to August 1896, the gold mine processed just over 5000 tons of ore. In the short time the company won 33 kg of raw gold. == Bankruptcy ==