The Crocker Association is the most extensive association in Sabah and it is almost continuous from the Kudat and Bengkoka Peninsulas in the northeast to the Kalimantan boundary in the south.
It occurs on extensive mountain ranges, notably the Crocker Range and the associated Sir James Brooke, Witti and Maitland Ranges, and the Brassey Range. Amplitudes are in excess of 300 m and slopes are normally greater than 25°. Ridge crest and valley bottoms are narrow and landslips are common. The mountains are formed of interbedded sandstone and mudstone.
Much of the association is under lowland dipterocarp forest.
The association is quite unsuitable for agricultural development largely because of the steepness of the majority of slopes. Other limitations are identical to those described in the Lokan Association.