It has a lengthy snout and moderately long tail and lacks a pseudosiphon in the claspers.

It is morphologically similar to two other Alaskan skates, Bathyraja violacea and Rhinoraja taranetzi, but can be distinguished based on coloration patterns.

The dorsal surface of the disc has uniformly dense coverage of dermal denticles.

[4] Bathyraja mariposa has been estimated to have a population density of approximately 0.34 individuals per square kilometer in the Aleutian islands.

Trawl surveys have not uncovered this species outside of that region and appears to be found principally in the central Aleutians.