Still in use I believe...... have relatives living in McClendontown,PA.....one favorite Aunt we alway stayed with still uses coal......visiting her is a blast into the past....there is a coal furnace in the basement you access from the outside only, and you would have to go down every night and "bank" the furnace before bed, while sleeping you would hear the chain drive chinking along the rafters opening the dampers as heat was required.....in 1990, she just got hot water inside and a indoor bathroom, outhouse is still there and useable, but God love her, its basic living and what their used to out there....before indoor plumbing we used to heat water on the stove for a big basintub to take baths in the kitchen, and washed clothes in her Maytag wringer, not to mention wiping down the lines from soot before you hung out the clothes.....it is always great to go back home to visit!....not much has changed thru out the years
one thing to remember was the coal was stored outside, which had to be kept covered, otherwise local vermin and cats would use it as a toilet, and when you would burn the coal, the smell would fill the house.....