Gregson (1956) describes this genus as follows: “Ornate ticks with eyes and festoons. Anal groove posterior to anus. Basiacapituli of adults rectangular (of nymphs, triangular or rectangular). Palpi short and broad or moderate in width. Coxae I to IV increasing in size progressively. Coxa I bifid. Males with no ventral plates.” This species resembles the Rocky Mountain wood tick (Dermacentor andersoni) in size and appearance (Higgins 1999). According to Gregson (1956), this species is variable in colour and sclerotization, and specimens from “Vancouver Island have spiracles much smaller than those of the mainland”. He indicates that the winter appearance is helpful in identification: “spiracles of the adults are typically rounded and divided into goblets much larger than those of D. andersoni. The basal capituli of the nymphs lack the sharp lateral points found in D. andersoni”.