The carapace reaches a width of about 5 centimetres (2 in), and is widest at the 7th or 8th lateral tooth.

[3] Glebocarcinus oregonensis is found mostly in crevices, holes (dead barnacles) and under rocks.

[2] They are nocturnal feeders, feeding mostly on small barnacles, snails, bivalves, worms, green algae and Pacific oysters.

[3] Predators include Pacific cod, river otters and red rock crab.

[3] Breeding occurs during the summer, and the Puget Sound females carry eggs from November to May.