Rainbow trout originally lived in the Sierra Nevada mountain range in the U.S. However, they were introduced to North Carolina in the 1880s and since then have been stocked in rivers and streams all over the eastern U.S. They get their name because of a pinkish band that spans the length of either side of the fish, amid blackish spots. They may also have a pink or red gill cover. Typical rainbow trout are about 10 inches in length, though occasionally larger fish are found. They do best in clean, cool water with a bit of current.

An interesting fact about rainbow trout is that there are two forms which sometimes share the same habitat. They're the same species, but the 'steelhead' trout migrate to the ocean after mating season and they lose the red band on their sides. Also, they're more silvery than rainbow trout and a bit larger. Because of their superior size, when they do return to the rivers, they dominate the territory.

A common mistake about rainbow trout is that 'redband' trout are the same thing as rainbow trout. While they do appear quite similar in appearance, redband trout are actually a subspecies of rainbows with larger spots and darker colors.

Rainbow trout can be found almost all across the United States, from the Pacific Coast leading all the way down to Mexico, as well as in the north east. Overall, there are six main subspecies of rainbow trout in the western United States alone. These are the Columbia River red band trout, the California golden trout, the Kern & Little Kern golden trout, the Sacramento red band trout, the Coastal rainbow trout, and the Kamchatkan rainbow trout.

Golden rainbow trout (not to be confused with the naturally occurring 'golden trout') and palomino trout have been bred deliberately to cause the color variations. They're predominantly yellowish, without the typical green field and black spots, but they do still have the red stripe along their side. Palamino trout are a cross between golden rainbows and redbands, giving them their mixed colors.

Unlike similar species, rainbow trout do not die after spawning. In fact, the can sometimes spawn up to four times in their lifetime. However, all subspecies of rainbow trout go through changes during or when preparing to spawn. They change color and the shape of their head and mouth changes as well.

On the whole, rainbow trout are considered the backbone of American fishing. Both the rainbows and the steelheads are much sought-after by anglers, both as a source of food and for the intense fight they put up once caught on a line. They're so aggressive that they often jump from the water when hooked.