Mining has had a substantial environmental impact in some areas of Australia. Historically, the Victorian gold rush was the start of the economic growth of the country, leading to major increases in population. However, it also resulted in deforestation, consequent erosion, and pollution in the areas that were mined. The effects on the landscape near Bendigo and Ballarat can still be seen today. Queenstown, Tasmania's mountains were also completely denuded through a combination of logging and pollution from a mine smelter, and remain bare today. It is estimated that 10 million hectares of land have been affected throughout the history of mining in Australia. Because Australia's mines are distributed across varying climates the knowledge gained from one mine's restoration does not easily extrapolate to other sites.