Traditional approaches to the documentation of indigenous astronomical knowledge often assume a one-to-one or near one-to-one correspondence between indigenous and classical constellation terms. Only a single constellation, equated with the Big Dipper, is robustly attested across the Northern Dene languages. Here we provide evidence from Gwich’in (Dene) that shows that the equation of this single Gwich’in constellation with the classical constellation is only partial. The Gwich’in constellation yahdii is actually a whole-sky constellation that maps nearly the entire sky. The Big Dipper is the tail of yahdii, and the remaining stars in the constellation are identified by other Gwich’in body-part terms, forming a unified functional conceptualization of the sky. Our work demonstrates how observational and cultural biases can prejudice the description of cultural astronomy. Dene astronomy is much richer than has been previously claimed and provides the first well-documented indigenous example of a whole-sky constellation.