At the height of the mining, Ouray had more than 30 active mines.
There are not many active mines near Central City.
Today it houses a honeycombed inferno of 70 active mines over the old colonial city.
There is at least one active mine for gold and silver located on a 6 km2 concession.
Reserves in these active mines total 195 million tonnes (as at 1 January 2012).
Today, the area is marked by mining remains, but there are no active mines.
Enemy troops foolish enough to try to pick up an active mine for re-use will be killed.
There are more than 110 million active mines, distributed among 70 countries.
By 1964, the line served just one active mine, operating on a limited basis.
There are no active underground mines in Clearfield County as of 2007.