Almost one-quarter of freehold land in the Muswellbrook Local Government Area and large chunks of other parts of northern NSW are now owned or occupied by coal companies, a survey of land records by Lock the Gate shows.

The holdings, amounting to 284,093 hectares across eight local government areas, include 20,470 hectares of leases in state forests and other public lands.

Prize land: Mining at Muswellbrook in the Hunter Valley. Credit:Rob Homer

Mining also accounts for significant shares of agricultural land in those two areas, with 23-27 per cent of the Biophysical Strategic Agricultural Land held by the coal companies. The tally includes areas to be set aside to offset mine destruction of threatened vegetation.

"Some people will get a big shock when they see these figures," said Stewart Mitchell, a long-time resident of Bulga near three big coalmines in the Singleton area.