From the U.S. Forest Service:

“Brewer spruce is a California native, endemic conifer. It has a distinctive, drooping appearance caused by the presence of thousands of long, ropelike branches hanging from all but the topmost horizontal limbs. At maturity, Brewer spruces usually reaches 80 to 100 feet (24-30 m) in height, but can reach up to 172 feet (52 m) in height. Diameters range from approximately 3.8 feet (117 cm) to up to 4.5 feet (1.35 m) in some areas. The bark is thin and broken into long, thin, appressed scales. The leaves are obtuse, flat on top, and rounded underneath, and spread from all sides of the branchlets. The male cones are stalked and oblong (3 to 4 inches [7-10 cm] long). The seeds are 0.12 inch (3 mm) long. The root system generally is shallow; however, on deeper soils, a few vertical roots may extend several meters. Brewer spruce can live as long as 900 years.

Brewer spruce is endemic to the Klamath region of northwestern California and adjacent Oregon. It is distributed from from Del Norte, Trinity, and Siskiyou counties in California to Curry and Josephine counties in Oregon. The best developed stands are located on high ridges and upper valleys of the Klamath, Shasta-Trinity, and Six Rivers National Forests of California and in the Siskiyou and Rogue River National Forests of Oregon. Despite its restricted distribution, Brewer spruce has a broad ecological amplitude. Its apparent limitations are high water tables and frequent fires. Brewer spruce is quite tolerant of soil moisture stress, cold temperatures, low light, low-fertility soils, and snow. Although Brewer spruce can tolerate considerable soil moisture stress, it is sensitive to high evaporation demands. Under such demand, stomata close, halting photosynthesis.

Brewer spruce grows in a climate of cold, wet winters and warm, relatively dry summers with respective temperature ranges of 30 to 41 degrees Fahrenheit (-1 to 5 deg C) and 52 to 68 degrees Fahrenheit (11-20 deg C). Annual precipitation varies between 39 and 110 inches (1,000-2,800 mm. Brewer spruce stands occur on north-, south-, east-, and west-facing slopes, but the preferred habitat is steep, north-facing slopes. Brewer spruce occurs on rocky ridges, cold hollows, and on dry talus and moraines. It never occurs in areas where the soils are saturated during the growing season, such as boggy or wet areas. The slope is generally 11 to 70 percent.

Brewer spruce grows on soils developed from sedimentary, granitic, serpentine, and metavolcanic rock. Most soils are shallow, rocky, and undeveloped; however, Brewer spruce does occur on deeper soils. Soil pH ranges between 4.6 and 7.2 on mica schist, meta volcanic, granitic, and ultrabasic soils. Soil depth varies between 12 and 50 inches (6.5-127 cm). Kruckeberg lists Brewer spruce as an indicator of serpentine soils. Heavy metals, especially iron and nickel, can attain high levels in soil and plant tissues of Brewer spruce.”