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Rainbow Trout

The rainbow trout is one of Montana's most popular fish, and there are a lot of reasons why that is true. Rainbows grow large, are found over a large part of the state, and feed aggressively, which means people who fish for them have a better chance of catching a rainbow trout than they do of catching some of the other of Montana's trout species.

But there are some things about rainbows that not everyone knows. Many people think that rainbow trout have always been a part of the fishing scene in Montana. But that's not totally true. Rainbows are not native to Montana. That means that they were brought into the state by humans. The first rainbows arrived in Montana in the late 1800's. They came from west-coast states like Oregon, Washington, and California. Montana does have one sub-species of rainbow trout that is native to the state. It is called the RedBand Rainbow, and was originally found in the far northwest corner of the state.

Clean, cold water is important for rainbow trout. They prefer water temperatures to be about 55°. If it gets too warm, it is hard for the rainbows to live. If the water never warms to temperatures much above freezing, the trout grow very slowly, and may never reach a very large size. Trout are cold-blooded animals, like snakes and turtles, so they cannot keep their body at a steady temperature like humans and other mammals are able to do.

Rainbow Trout image. Rainbow Trout

Rainbow trout spawn, or lay their eggs in the spring. They usually look for a place with enough current to keep their eggs well supplied with oxygen, and then the parents build a redd, or nest. After they lay their eggs in the nest, they cover them with gravel, and leave. When the fry, or young trout hatch, they are very small and cannot swim well. They must hide in the cracks of the bottom. As they grow, they become better swimmers, and soon begin spending time in other areas of the stream. They must always be careful, since there are many predators that like nothing better than a meal of rainbow trout. Larger trout, otters, and birds like ospreys and mergansers all feed on rainbow trout.

Many of us also act like predators, since we like to fish for rainbow trout. Although much of the diet of rainbow trout is made up of insects, they can be caught on lots of different lures and baits. Fly fishermen like to catch rainbows on dry flies, which float on the surface of the water, and wet flies, which sink below the surface. Rainbows can be caught on lures like spinners and spoons, and one of the best baits for rainbows, like many other fish, is still just a few worms on a hook. Sometimes rainbow trout live in lakes or reservoirs, and their diet is made up of smaller fish. In that case, anglers might use a plug, which is designed to look like a small baitfish. Sometimes rainbows will even eat other rainbow trout, so one of the best baits is a plug painted to look like a small trout.

There are many ways to fish for them, and plenty of places to find rainbow trout in Montana. The state record rainbow was caught in 1997 from the Kootenai River, and weighed over 33 pounds.