Born to farming parents in Missouri in 1820, George Hearst would go on to have a net worth equal to 1/712th of the GNP of the entire US, and serve two terms as a California senator, following a career as one of the first famous miners in the US.
Hearst moved to California in 1850 as part of the 19th century Gold Rush, where he worked as a quartz miner and prospector for nine years, before purchasing a stake in the Ophir silver mine in Nevada. By the end of the year, the mine had produced 38 tons of silver ore, which was smelted in San Francisco and sold for a profit of $91,000, equivalent to $2.5m in 2016 money.
As part of the group Hearst, Haggin, Tevis and Co., he went on to invest in the Pacific mine in New Mexico, the Anaconda mine in Montana, the Homstake mine in South Dakota, and the Ontario silver mine in Utah, the last of which contributed $12m to his personal fortune of $19m at the time of his death.
Following an unsuccessful campaign for the governorship of California in 1882, his wealth and renown led to his appointment to the US Senate in 1886, following the death of John Miller. He would be elected for a second term in 1887, and served until his death in 1891.
More recently, Hearst was portrayed as a villain in the HBO television series Deadwood in his pursuit for the Anaconda mine. He was inducted into the American Mining Hall of Fame in 1988.
While the British Isles enjoyed a gold mining boom in Wales, some of its natives sought careers aboard. Born in Scotland, Sleath moved to Australia as a teenager in 1877, where he took up a career in mining that would see him dubbed the ‘Hero of 92’ for his role in leading a miners’ strike in 1892.
He was made president of the New South Wales Amalgamated Miners’ Association (AMA) in 1889, where his aggressive recruitment strategies led to 2,500 of the state’s 3,000 miners joining the AMA. In November 1889 he clashed with BHP for the first time; the company had been founded four years previously to extract silver and lead from the Broken Hill mine, but capitulated to Sleath’s demands to compel its non-union workers to join the union.
By 1892, low metal prices and the depletion of ore reserves led mining companies to propose the introduction of contracts for underground work, in violation of the terms Sleath had negotiated following his run-in with BHP in 1889.
Sleath again led negotiations, even going so far as to attend a meeting of BHP shareholders in July 1892, but was ultimately arrested for inciting riot and conspiracy, along with other AMA leaders.
He was released the following year, and went on to serve as a member of parliament for the Labor Party, and then as an independent candidate.
He died in 1922 and was enshrined in the Australian Mining Hall of Fame.
John Van Nostrand Dorr
Born in New Jersey in 1872, Dorr worked with Thomas Edison before becoming one of the mining industry’s most prolific inventors, securing over 20 patents for new devices built to improve mines.
While working at gold mills in South Dakota and Colorado, he invented the Dorr Classifier, a method for separating fine solids from liquid, which had immediate impacts for the mining industry, as well as in sewage treatment, water purification and sugar production. He also worked on the Dorr Thickener, a process that enabled the continuous thickening of ore slurry, and the Dorr Air-lift Agitator, which continually mixed liquids.
Over the course of his career, Dorr was awarded the John Scott Medal for his engineering work, the Chemical Industry Medal for his contributions to the industry, and the Perkin Medal for the financial benefits of his inventions.
He died in 1962 and was the fourth person to be inducted into the American Mining Hall of Fame, in 1988.
Kathleen Creighton Starr Rice was born in Ontario in 1882. She rose to fame for her vast exploration projects, covering 800km on foot, dog sled and canoe to find zinc, vanadium, gold and nickel deposits throughout Canada.
The Canadian Mining Hall of Fame describes her as an “innovative dog trainer”, and an explorer with a strong respect for First Nations groups, who often worked with her on her journeys.
Rice made considerable contributions to mining projects once she had found deposits; she staked 16 nickel and copper claims on Rice Island in Weskusko Lake in central Manitoba between 1920 and 1922, which were valued at $5m in 1925. She then formed the Rice Island Nickel Company in 1928, in which she held a stake for the next 30 years.
She was also responsible for introducing the use of borax crystals to North America, which are used today in metallurgical processes as a flux, an agent used to clean or purify a chemical substance. Rice also produced plans for a hydropower plant at Wekusko Falls, where she made her first nickel and copper discoveries.
In 1962, Rice moved to a nursing home in Manitoba following years of living in isolation in the wilderness. She died in 1963 and was inducted to the Canadian Mining Hall of Fame in 2013.
The 31st President of the United States spent much of his early life working in the mining industry. Hoover graduated from Stanford with a degree in geology in 1895, before working with the US Geological Survey and Bewick, Moreing and Co., a London-based gold miner with operations in Western Australia.
Hoover then served as the chief engineer for the Chinese Bureau of Mines and general manager of the Chinese Engineering and Mining Corporation, before returning to the US and making money through investing in and rehabilitating struggling mining operations around the world.
By 1914, his mining projects had granted him a personal fortune of $4m, equivalent to $97m in 2017 money.
Hoover frequently wrote and lectured on mining; some of the talks he gave at Columbia and Stanford universities were published in the 1909 textbook Principles of Mining.
Together with his wife Lou, he completed an English translation of De re metallica, a 16th century text on mining practices and processes originally written in Latin by the German metallurgist Georgius Agricola. The translation work took five years, and the couple was awarded the first Gold Medal of the Mining and Metallurgical Society in 1914.
Hoover went on to work in the US Government, as director of the food administration, secretary of commerce, and ultimately president, from 1929 to 1933. He died in 1964, and was inducted into the American Mining Hall of Fame alongside Hearst and Dorr in 1988.