All American forms, aside from possibly the Tule and Roosevelt elk, seem to belong to one subspecies (Cervus canadensis canadensis). Even the Siberian elk (Cervus canadensis sibiricus) are more or less identical to the American forms and therefore may belong to this subspecies, too.
The elk or wapiti (Cervus canadensis) is one of the largest species within the deer family, Cervidae, in the world, and one of the largest land mammals in North America and Eastern Asia.This animal should not be confused with the still larger moose (Alces alces) to which the name "elk" applies in British English and in reference to populations in Eurasia.
Of the six subspecies of elk known to have inhabited North America in historical times, four remain, including the Roosevelt (C. canadensis roosevelti), Tule (C. canadensis nannodes), Manitoban (C. canadensis manitobensis) and Rocky Mountain (C. canadensis nelsoni).
Roosevelt Elk (Cervus Canadensis roosevelti) Roosevelt Elk (Cervus Canadensis roosevelti) The Roosevelt elk also known as Olympic elk, is the largest of the four surviving subspecies of elk in North America, they live in the rain forests of the Pacific Northwest and Vancouver Island.
The tule elk (Cervus canadensis nannodes) is a subspecies of elk found only in California, ranging from the grasslands and marshlands of the Central Valley to the grassy hills on the coast. The subspecies name derives from the tule, a species of sedge native to freshwater marshes on which the Tule elk feeds.