[2][3] Pacific giant salamanders are defined by their wide protruding eyes, costal grooves, thick arms, and dark background coloring.

Dicamptodon have a snout-vent-length (SVL) of 350 mm (14 in), a broad head, laterally flexible flattened tails, paired premaxillae that are separate from the nasals, and the aquatic larvae have gills.

They are commonly found in various lotic environments in altitudes ranging from 0 to 7000 feet above sea level in the Pacific Northwest and Northern California.

[7] Pacific giant salamanders also utilize terrestrial refuge sites such as decaying wood, burrows, or under rocks.

[8] The genus Dicamptodon was formerly thought to contain two species, Cope's giant salamander (D. copei) on the Olympic Peninsula, Washington, and the Pacific giant salamander (D. ensatus) which consisted of three geographic populations, an Idaho isolate, a group in northern California, and a group in Oregon and Washington.