The Beatton River, Fontas River, Fort Nelson, Maxhamish Lake and Petitot River map areas occupy the northeast corner of the province and contain 4 documented mineral occurrences.  The map area lies entirely within the Foreland Belt and is dominated by flat-lying and poorly exposed clastic rocks of the Cretaceous Fort St. John Group and the Upper Cretaceous Dunvegan and Kotaneelee formations.  The Fort St. John Group comprises recessive shale and siltstone; the Dunvegan Formation consists of cliff-forming sandstone and conglomerate; and the Kotaneelee Formation is made up of dark grey marine shale and minor sandstone.

Occurrences in the map area include 2 showings of native sulphur in petroleum well holes at depth; barite fracture fillings in dolomite; and a bed of coal exposed in a pit that was subsequently filled in.