I am looking for detailed maps showing the mines dug underneath a lot
I may purchase.  Normally, someone would just buy mine subsidence
insurance and forget about the particulars of what is underneath. 
However, the neighbor to the lot told me that he believed the amount
of ground cover was less than 50' for some parts of this lot, and for
that little ground cover I will need detailed information.  The
neighbor also believed that there used to be a mine shaft entrance
near the front of the lot.

I have gone through the bureau of mines and they were not able to
provide detailed information - only general area that is undermined
and very vague ground cover levels.

The lot is located on Baldwin Rd, Carnegie, PA, USA.  The road
frontage runs between these two coordinates:

40deg 25'12.29" North
80deg 08'40.27" West
and
40deg 25'12.71" North
80deg 08'38.14" West

I will need a detailed mine map showing depths and the location of
those coordinates.