Apache trout are found in streams that flow through mixed conifer forests and mountain meadows at elevations above 5,905 to 6,900 feet in elevation (1,800 to 2,100 meters). They require cold and clean water, generally below 77°F and spawning habitat consists of gravels free of fine sediment.

Apache trout seek out rearing habitat along stream margins and other areas that contain velocity refuges, or slow moving water, pools, and cover elements, like undercut banks, boulders, that provide juveniles and adults places to seek refuge while they feed and grow. Adequate stream flow and shade are generally required to maintain pools that are frequently used by Apache trout during periods of drought and temperature extremes. Pure populations of Apache trout are typically above 6,900 feet in elevation (2,100 meters) and often above natural barriers like waterfalls, keeping non-native trout from invading into those habitats. This, along with closed access to fishing, have resulted in 17 relict populations of Apache trout that remain free of hybridization, with 30 total pure populations.

Apache Trout have a fusiform body, meaning that it is wide in the middle and tapering at both ends, and a large dorsal fin.

Measurements
Fry length: Less than 3.9 inches (100 millimeters)
Juvenile length: 3.9 to 5.1 inches (100 to 129 millimeters)
Adults length: Greater than or equal to 5.1 inches (130 millimeters)

Apache trout have spots on the body, that are pronounced and often uniformly spaced, above and below the lateral line. These trout are predominately a golden yellow or yellow-olive color with tints of purple and pink. Two black spots are located horizontally on either side of the pupil, creating the image of a black band through the eye. A red or pink lateral band is usually absent and parr marks or dark vertical marks, can be retained in adults. Dorsal, pelvic and anal fins have conspicuous cream or yellowish tips. A yellow cutthroat mark is usually present and basibranchial teeth, which are located on the base of the tongue, are occasionally present.

The maximum reported weight for an Apache trout is 5 pounds, 4 ounces.

Apache trout are reproductively mature around 3 years old. The annual survival rate for Apache trout ranges from 48 to 70%.

The life span of an Apache trout is typically five years, although a recent age and growth study suggests they can live 9 years or more.

Spawning occurs from March through mid-June and varies with stream elevation. Females excavate redds, or nests, in the gravel. After fertilization by male Apache trout, the eggs are covered with gravel. Incubation lasts about 30 days and young Apache trout emerge from their redds after about 60 days. Each female can lay 200 to 600 eggs.

Other Oncorhynchus species are closely related to the Apache trout and have been shown to hybridize with them. Apache trout and Gila trout are believed to have derived from a common ancestor that gained access to the Gila River from the Gulf of America.

Apache trout are largely opportunistic and feed on a variety of aquatic and terrestrial organisms.

Adult Apache trout and larger juveniles generally use pool and eddy habitats in deeper or higher velocity water. Fry and smaller juveniles are found in low velocity water that is generally shallower.