The Roper, Limmen Bight, McArthur, Calvert, Nicholson, Leichhardt, Flinders, Norman, Gilbert, Staaten, and Mitchell rivers drain into the Gulf of Carpentaria.

The monsoon winds bring rainfall during the Southern Hemisphere summer from November to March, followed by a dry season during the rest of the year.

[2][6] The vegetation of the ecoregion includes grasslands, savanna, open woodlands, and small patches of forest.

In the southwestern Gulf Plains, along the northern edge of the Mount Isa Inlier, there is a narrow belt of Eucalyptus and Melaleuca woodlands, with a grassy understory dominated by Chrysopogon fallax.

On the higher plateau remnants in the southeast, there are woodlands of narrow-leaved ironbark (Eucalyptus crebra) and bloodwood (Corymbia spp.

The Carpentarian rock rat (Zyzomys palatalis) is endemic to the ecoregion, and found only in patches of ravine forest and vine thickets on sandstone outcrops in Wollogorang Station.