Kongsberg Silver Mines
The silver mines of Kongsberg, in Buskerud county in Norway, constitute the largest mining field in Norway, with over 80 different mines. It was the largest pre-industrial working place in Norway, with over 4,000 workers at its peak in the 1770s and supplied over 10% of the gross national product of the Danish–Norwegian union during its 335-year-long history: over 450,000 man-years were expended in the production.
Sulitjelma
In 1887, the Swedish industrialist and entrepreneur Nils Persson (1836-1916) bought the mineral rights to those findings and the mining era began.
Sulitjelma Gruber was founded in 1891 as a Norwegian limited company to mine the area's minerals. In addition to the mines themselves, there was also a plant for processing the ore, a smelting plant, a conveying plant, as well as all the other necessary service institutions needed to support the growing population of the community. By the early 20th century, it was the largest mining company in the country—and the second largest Norwegian industrial company. At its peak in 1913, the company had 1,750 employees.
Over time it became necessary to go deeper into the mountain to reach the ore. This increased the cost of the operations. When the mining license expired in 1983, the state took over the operation under the name of Sulitjelma Bergverk A/S. In 1991, all mining in Sulitjelma was stopped as the costs of extraction became greater than the value of the ore on the market. The remaining ore deposits still constitute the largest known deposit of copper in Norway.
The construction of the Sulitjelma Line railway began in May 1891 when the mining company in Sulitjelma decided to build a railway between the villages of Sjønstå and Fossen. The line was the first in Northern Norway. The expansion of the mine into the mountains at Fagerli began in 1912, and at the same time the railway gauge was increased from to . The railroad line was closed on 22 July 1972. The tracks were removed and the former trackbed was converted into a roadway. Norwegian County Road 830 opened to traffic in 1975.