This small, larva-like fish is found only in Cultus Lake in British Columbia. Cultus Lake is a low-level montane lake in southwestern British Columbia's Fraser River watershed; this fish species restricts itself to the deeper parts of the lake.

A full-grown adult Cultus pygmy sculpin is roughly 50 millimeters long and resembles a larva. The fish runs brown to grey on top, marked with dark blotches; its bottom is more or less white. Spawning males are darker-coloured and boast an orange band on the first dorsal fin. The species has a large head, heavy body and small pelvic fins, a long anal fin, two soft dorsal fins, and good-sized pectoral fins with small prickles behind them. Two or three dark blotches appear beneath the second dorsal fin. Adult fins have bar-shaped pigments.