[7] It was long thought to be either a race of Peary caribou or a hybrid or intergrade between Peary and barren-ground caribou (e.g., Manning 1960),[8] for which reason some authorities called it (informally, since it was never officially described according to the rules of the International Commission on Zoological Nomenclature) Rangifer tarandus groenlandicus x pearyi.

[9] Genetic and other data showed it unequivocally to be a distinct race of barren-ground caribou, then known as Rangifer tarandus groenlandicus.

[13] Its unique morphology, behavior and ecology and its genetic distance from other herds of barren-ground caribou, suggest that it may warrant subspecific designation, but it has yet to be formally described.

The main distribution during the calving and fall seasons is on Victoria Island and since the 1960s Dolphin-Union Caribou resumed their migration to winter on the Nunavut-NWT mainland.

In summer the herd occupies Victoria Island where it is often on "beach ridges and river valley slopes.

[2] There are a number of concerns including potential over-harvesting by hunting, "over-grazing in areas where caribou wait before migrating to the mainland for the winter"; "local knowledge has demonstrated an increase of predators across summer ranges"; "an unknown number of caribou die every fall breaking through the ice crossing to the mainland"; "changes to sea ice freeze-up and break-up due to climate change could threaten migration; and "Increased ship traffic through Dolphin and Union Strait may affect ice formation and caribou migration.