Juniperus scopulorum is a perennial, evergreen gymnosperm native to North America. The species grows as a shrub or tree to 30 feet (10 m) or more and has thin, fibrous bark that usually shreds with age. In the open, trees are stubby and broadly pyramidal with branches to ground level. In shaded areas, the trunk is less tapered and foliage arranges in "weeping sprays". Leaves are scalelike and 0.03-0.11 inch (1-3 mm) long or needlelike and 0.11-0.47 inch (3-12 mm) long.

Trees or shrubs in the genus Thuja in the cypress family Cupressaceae are commonly known as Arborvitae, and sometimes "cedar", although they are not cedars.  There are five species in the genus, two native to North America and three native to eastern Asia.

Evergreen, coniferous trees growing to 10–60 m tall, with stringy-textured reddish-brown bark. The shoots are flat, with side shoots only in a single plane. The leaves are scale-like 1–10 mm long, except young seedlings in their first year, which have needle-like leaves. The scale leaves are arranged in alternating decussate pairs in four rows along the twigs. The male cones are small, inconspicuous, and are located at the tips of the twigs. The female cones start out similarly inconspicuous, but grow to about 1-2 cm long at maturity when 6–8 months old; they have 6-12 overlapping, thin, leathery scales, each scale bearing 1–2 small seeds with a pair of narrow lateral wings.

Thuja species are used as food plants by the larvae of some Lepidoptera species including Autumnal Moth, The Engrailed and Juniper Pug. The foliage is also readily eaten by deer, which where deer population density is high can adversely affect the growth of young trees.

Arborvitae wood is light, soft and aromatic. It can be easily split and resists decay. The wood has been used for many applications from making chests that repel moths to shingles. Thuja poles are also often used to make fence posts and rails. The wood of Thuja plicata is commonly used for guitarsoundboards. The foliage of thujas is rich in Vitamin C, and was used by Native Americans and early European explorers as a cure for scurvy. --adapted from Wikipedia

Juniper prefers calcareous and somewhat alkaline soils and grows best on moist, deep soils. It survives extremes of temperature well. Rocky Mountain juniper is considered hardy except for "burning" of foliage on trees exposed to northwest winds during winter in the northern Great Plains. It can tolerate shade when young, but becomes intolerant later in life. It is more drought tolerant than eastern redcedar and less so than other tree junipers in the west. In fact, during the 1930s drought, Rocky Mountain juniper woodland maintained and expanded range in the western Dakotas.

This plant grows throughout the drier mountains and foothills of British Columbia and Alberta; south through the Great Basin and Rocky Mountains to Arizona, New Mexico, and western Texas; and north across eastern Colorado, western Nebraska and North Dakota, Montana, and into Saskatchewan. It is also found on Vancouver and other Puget Sound islands, as well as the surrounding mainland.

Juniperus scopulorum is found over most of the range of pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands. It is a major tree species in the higher elevations of pinyon-juniper woodlands in Colorado, northern New Mexico, and Arizona, and locally in Nevada and Utah. In pinyon-juniper woodlands, it is found in association with other juniper species such as alligator juniper, oneseed juniper, and Utah juniper, as well as Colorado pinyon (Pinus edulis), Mexican pinyon (P. cembroides), and singleleaf pinyon (P. monophylla).

Rocky Mountain juniper communities in the northern Great Plains are often restricted to steep, north-facing slopes. Individuals may be scattered across other areas in mountains and canyons throughout the Rocky Mountain region, such as rocky outcrops, butte tops, draws, and floodplains [19,49,58,109]. Rocky Mountain juniper forms open woodland with sagebrush and grasses, and it is often found mixed with Douglas-fir (Pseudotsuga menziesii), Gambel oak (Quercus gambelii), or ponderosa pine (Pinus ponderosa). It is also found along waterways in pure stands or as understory in the cottonwood (Populus spp.)-willow (Salix spp.) habitat type. It forms pure stands at middle and low elevations in the northern part of its range. (2)