The wapiti, or elk, is one of the largest members of the deer family. Only the moose is larger. There are two subspecies of elk in Washington:
- Roosevelt elk
- Rocky Mountain elk
The Roosevelt elk is found in western Washington, while the Rocky Mountain elk is found in eastern Washington. The Rocky Mountain elk is slightly lighter colored than the Roosevelt elk, and it is slightly smaller in body size. The most distinctive feature on both subspecies of elk is the rump patch, which is a pale white or cream color. Adult bull elk can weigh as much as 1,100 pounds, although the average weight is usually between 500-700 pounds.
The elk herds of Washington are now found in ten major areas of the state. The two biggest herds are the Yakima (12,000 animals) and Mount St. Helens (11,000–13,000 animals). The Olympic (7,000–9,000 animals), Willapa Hills (7,000–9,000 animals), Colockum (5,600 animals), Blue Mountains (5,300 animals), North Rainier (1,500–2,500 animals), South Rainier (1,500–2,500 animals), Selkirk (1,000–2,000 animals), and North Cascades (1,250 animals) comprise the remaining populations.
In general, grasses and sedges are the main items in the diet of wild elk, although local habitat conditions may cause this to vary. In habitats which are overgrazed, elk will rely heavily on browse and will include in their diet such shrubs and trees as fir, maple, serviceberry, dogwood, aspen, pine, willow, and sage.
As with deer, tooth analysis is the best way to determine the age of individual animals. Antler size is not an accurate way to age bull elk.
Natural enemies of elk in Washington include the cougar, wolves, coyote, dogs, bobcat, bear, and golden eagle. The latter three animals will generally attack and consume only very young calves or severely injured animals.