Rock Mountain Elk (Cervus elaphus)
In Oregon, Rocky Mountain Elk are found east of the Cascade Range and Roosevelt Elk west of the Cascade Range. The Rocky Mountain Elk is smaller and lighter in color than the Roosevelt Elk. Elk in general inhabit forests, meadows, mountain valleys, and foothills. They may once have occupied shrub lands of eastern Oregon. Elk are primarily grazing animals, preferring a diet of grasses.. In winter, they turn to browsing the tips of twigs from willow, alder, aspen, oak, or other woody vegetation.  

Adult females, their current offspring, and their female offspring of the previous year form herds that tend to remain within relatively small and distinct areas. Leadership of these herds usually is provided by an older female with an offspring, but other females with offspring assume leadership duties at times.

Male elk, especially the larger ones, tend to be solitary most of the year; however, during May and June when antler growth is rapid, males, including larger ones, sometimes form herds. The antlers become polished in July, at which time activity increases as males commence to search for untended females or those tended by less formidable males. Breeding season is from early September to mid-November.

In winter, elk migrate to the Sunriver area and south after the first heavy snow. The spring migration depends on snow late March early April.
Photo: Female Elk – Tony Hisgett

Mule Deer (Odocoileus hemionus hemionus)
In eastern Oregon, Mule Deer once ranged into sagebrush plains in canyons or rimrock, but they now are confined mainly to mountain ranges wherever there is enough cover to protect them from summer heat and predators. The Mule Deer winter migration to lower elevation starts around the first or second week in October. In late April, Mule Deer migrate toward Wickiup reservoir and Mount Jefferson wilderness. There are small groups of deer that inhabit residential areas all year.
Mule Deer are frequently consecrated in groups as many as 24 led by an older female.  They are active throughout the year, and concentrate their daily activities around dawn and dusk. During the reproductive season, most groups consist either of males or of adult females, their young-of-the-year, and female young of previous years. 

Mule Deer bucks rub scent glands on their head and necks against trees to advertise their presence.

Yearling and mature males begin growing antlers in the spring in response to day length.

The Black-tailed Deer in Western Oregon are a subspecies of Mule Deer.