Some coastal areas of the Northern Kimberly are formed of basalt, and the Mitchell Plateau and Bougainville Peninsula are overlain by a layer of bauxitic duricrust.

[6] The southern Dampierland region, which includes the Dampier Peninsula and the coastal plain extending to the southwest, are on deposits of red sand.

[2] The vegetation is mostly savanna and open woodland, which vary in species composition with rainfall, underlying soils, and exposure to fires.

[2] River valley lowlands with fine-textured clay and clay-loam soils are home to open woodlands characterized by trees of the genera Terminalia and Bauhinia, and grasslands of Chrysopogon, Aristida, and Dichanthium, with species of Xerochloa in wetter areas.

[2] Pindan is a plant community found on the Dampier Peninsula and elsewhere the southwestern portion of the ecoregion, typically in areas with red sandy soils.

Monsoon rainforest is composed of semi-deciduous or deciduous trees which lose their leaves towards the end of the dry season ("raingreen").

Monsoon rainforests are found behind coastal dunes, on hillsides and scree slopes, at the edges of swamps and rivers, and in gorges and gullies.

[6] In Northern Kimberley, monsoon rainforests are common on scree slopes at the bottom of escarpments, and at the edges of freshwater swamps and mangroves.

Common trees include Terminalia petiolaris, mangarr (Sersalisia sericea), banyan fig (Ficus virens var.

There are localized populations of Cupaniopsis anacardioides, Diospyros maritima, D. rugulosa, Pittosporum moluccanum, Trophis scandens, and Vitex glabrata.

[6] Coastal monsoon vine thickets extend from the Dampier Peninsula as far south as Broome, in areas with 600 mm or more of annual rainfall.

The endemic Cable Beach bloodwood (Corymbia paractia) is a characteristic tree, along with Goonj (Celtis philippensis), Croton habrophyllus, broad-leaved ballart (Exocarpos latifolius), karnbor (Melaleuca dealbata), marool or blackberry tree (Terminalia petiolaris), and mamajen (Mimusops elengi).

Common riparian trees include river red gum (Eucalyptus camaldulensis), Terminalia platyphylla, Nauclea orientalis, Melaleuca leucadendra, and species of Ficus, Alphitonia, Calophyllum, Canarium, Cryptocarya, Myristica, and Syzygium.

Native mammals include the agile wallaby (Macropus agilis), common wallaroo (Osphranter robustus), antilopine kangaroo (Osphranter antilopinus), northern quoll (Dasyurus hallucatus), bilby (Macrotis lagotis), short-beaked echidna (Tachyglossus aculeatus), northern brushtail possum (Trichosurus arnhemensis), common brushtail possum (Trichosurus vulpecula), rock-haunting ringtail possum (Petropseudes dahli), sugar glider (Petaurus breviceps), and pale field rat (Rattus tunneyi).

The golden bandicoot (Isoodon auratus) and golden-backed tree-rat (Mesembriomys macrurus) were once widespread in the ecoregion, but are now limited to Northern Kimberley.

The six endemic mammals are the Ningbing false antechinus (Pseudantechinus ningbing), scaly-tailed possum (Wyulda squamicaudata), monjon (Petrogale burbidgei), yellow-lipped bat (Vespadelus douglasorum), Kimberley mouse (Pseudomys laborifex), and Kimberley rock rat (Zyzomys woodwardi).

Lakes Argyle and Kununurra are artificial reservoirs on the Ord River which have become important dry-season refuges for birds.

The rocky northern coast and offshore islands are home to colony breeding sites for herons, cormorants, and other seabirds.

[2] The endemic lizards include seven species of geckoes (Diplodactylus mcmillani, Gehyra occidentalis, G. xenopus, Oedura filicipoda, O. gracilis, Amalosia obscura and Pseudothecadactylus cavaticus), four agamid lizards (Diporiphora convergens, D. pindan, D. superba, and Pogona microlepidota), and 13 skinks (Carlia johnstonei, Ctenotus burbidgei, C. mastigura, C. tantillus, C. decaneurus yampiensis, Egernia douglasi, Eremiascincus brongersmai, Lerista apoda, L. borealis, L. kalumburu, L. separanda, L. walkeri, and Cyclodomorphus maximus).