Rainbow Trout are native to the pacific regions of Northern Mexico, the western region of the United States and Canada, and up and around Alaska to the Kamchatka Peninsula in Russia. Because of their popularity as both a food fish and a sport fish, hatcheries have expanded this range worldwide, and rainbows are now found all over the world, including central and eastern US, New Zealand, Europe, and even parts of Africa.
Photo: Alaskan Rainbow by Kate Crump / Angler Alex Bradberry
Rainbow trout thrive in a number of different environments, from small streams to raging rivers, lakes, and some even go to the ocean. Ocean-run rainbows are called steelhead, and are another hugely popular sportfish that we'll focus on in a different article.
Photo Credit: Alex Bradberry
Fishing for rainbows will change depending on the season and location in which you’re fishing. In general, their metabolism slows in the winter, so your best luck is fishing warmer days and smaller flies, like zebra midges, prince nymphs, Hare’s Ears, stoneflies, and others.
As temperatures rise, trout will become more active and start eating larger insects and even small fish. Spring is a great time to fish larger stoneflies, leech patterns, sculpins, and even mice patterns in areas where mice are prevalent. You can also fish with dry flies, which many purist anglers prefer to fish exclusively. These are heavily dependent on matching the hatch in your area and can range in size from large (1-2") salmonflies down to tiny Adams flies. Larger rainbows will eat everything from tiny dry flies to larger bait fish; up to a third of their own body size. This is a great time of year to fish with large streamers, remaining mindful of your local trout population's spawning habits.
Once summer comes around, fishing can slow down if you’re in an area with high temperatures, as rainbows will dive deeper to find cooler waters. It’s important to keep temperatures in mind, especially in the summer. While safe handling of fish year round is a good habit to make, if you live in a warm climate then it’s often necessary to avoid fishing during the middle of the day, when temps are their highest. This allows the fish to rest and remain in the cool water they prefer; fishing in the early morning or evenings may be the best option.
If you’re in an area where salmon run, trout will switch to a diet of almost exclusively salmon eggs during the summer and fall. Now is the time to start beading, and you can match eggs per the chart below. Beads are made of plastic and can be wedged into your leader about 2-3" above your hook.
When fall rolls around, rainbows will often start bulking up for winter and once the salmon eggs are gone, salmon flesh is abundant. This is the perfect time to fish with flesh flies, as well as leeches again and patterns like the Dolly Llama can be particularly successful. Below is an example of a flesh fly tied with beads among the other materials.
Another necessary factor to consider in rainbow fishing is their spawning habits. Rainbow trout reproduce when they reach about two years of age, and will typically do so during late spring and early summer, as water temperatures start to rise. It's important for anglers to be mindful of these seasons, as fishing for rainbows during this time can be ethically questionable, especially in watersheds where their populations are vulnerable.
When out fishing, be mindful of trout (and other fish species') redds. Redds are depressions dug in gravel by female trout (hens) to lay their eggs. Typically trout will guard their redds heavily during mating and once eggs have been fertilized they will move on. Redds are visible to anglers due to their shape and the clean rocks that are left by the hen when she's digging. You can see what a redd looks like below.
Photo Credit: Sarah Baird
Some anglers will argue that fishing redds (aka capitalizing on the trouts' more aggressive behavior during spawning time) is just part of the fun of fishing. But, if you're a catch and release angler or conservation minded, it's important to consider that trout only have so much energy. When their energy is being spent fighting an angler, being held out of the water, sometimes losing the contents of their stomachs, and then being released, it isn't available for the strenuous activity of spawning. In order to allow successful spawning, it is best to leave trout alone during this time and to avoid walking, wading, or anchoring your way through their redds. Even though these practices are not technically illegal most of the time, respecting their space allows for better fitness within the trout population, which leads to more fish in the future!