Newly released papers from Margaret Thatcher's time at Number 10 have shown she may have planned to close over 70 pits.
The secret "hit-list" means that the government may have been looking at a further 50 closures than the 20 that were talked about by the government and National Coal Board.
The document reveals they wanted to close the mines over a three year period.
Arthur Scargill, then leader of the Yorkshire National Union of Miners, had always claimed the government were planning to close more mines than were being discussed publicly.
More top news
Jon Mitchell has Tuesday's late forecast
Leeds Utd players and staff have agreed to donated a day's wages to help pay for Toby Nye's treatment
A look back into the history of Huddersfield town when they were the Man United of the day in the 1920's and 30's.