pit mining is used
most often in mountainous areas. This is because in the mountains, coal seams
are irregular and localized. Oftentimes, explosives are used to
loosen the rock overburden, which is removed and initially stored outside of the
area being mined. Mining is then almost a vertical operation with pits becoming wider
and deeper as the mining progresses.
In the mountains and foothills of Alberta
and British Columbia, coal seams are twisted and faulted and usually mined from
large, open pit excavations. An open pit mine typically consists of a number of
different pits, which are developed sequentially. Because of the complex nature
of mountainous coal deposits, reclaiming the
site of an open pit mine can be more difficult than
reclaiming a strip mine on the plains.