The small thermal and pulverised coal injection coal producer said 44.7Mt of its total resources in the region were at a strip ratio of less than 10:1 while another 22.4Mt was less than 12:1.
Cockatoo owns 62.5% of the Baralaba open cut mine with resources at the operation increasing 280% to 23.2Mt over a 243-hectare area.
The Baralaba North project will extend this open cut mine, with resources increased by 194% to 45.8Mt.
To the south of the mine lies the Wonbindi project, with Cockatoo lifting these resources by 47% to 64.1Mt.
Cockatoo said exploration at Baralaba North and the Baralaba mine found resources which exceeded 7 kilometres in length and averaged 1km in width, remaining open to the north, south, east and west.
The Wonbindi resources remain similarly open and exceed 4.6km in length and average 1.8km wide.
Cockatoo is using four rigs to further define resources at the Baralaba mine and the Baralaba North project.
Cockatoo shares are up 3.5% to 44.5c this morning.