Many decades. If one was to find a mine from WWII, it might be still able to explode. Bombs from WWII are still found from time to time and are often still dangerous.
the ss346gh8 land mine
Beaver Land Mine Ride was created in 2000.
they are giving people knowledge of what to do if you see a land mine
because you walk up and down the runway doing all sorts of pose. i am improving this answer. the answer above mine is stupid. it clearly says the category is in airports. okay, so if a runway is active it is used for takeoffs and landings. (not much of an answer though)
Most are not. Mine is not. But some can be, yeah.
Oregon
Its means that someone is extremely active and never stops moving long enough for a fly to land on them.
Riddle, Oregon
Murfreesboro
Nevada
The Helen mine shutdown in June of 1998. There are still millions of tons of low grade ore left in the mine.
The most active gold mine in Australia is the Super Pit at Kalgoorlie, Western Australia. See the related question for more operating gold mines.