The Great Bull Migration

Every year bull trout begin their arduous journey up river towards their spawning grounds. Depending on the distance required to travel, this can begin in the early spring all the way up into the fall. Bulls can travel hundreds of miles from their wintering habitat, traversing looming waterfalls and snaking through tremendous currents, all to find a shallow stream bed where they will get their freak on.  

Typically, bull trout will travel upstream during cooler periods found during the evening while resting in deep pools during the heat of the day. As they begin their journey, their voracious appetite will start to wane and slowly their eating habits begin to transform. Prior to this change, bull trout spend the majority of their energy hunting prey. They hide deep within pools waiting to ambush unsuspecting meals. However, spawning will have bull trout focusing their energy on the journey. Meals will become less frequent and eventually you’ll hear fishermen use the term, “lock jaw,” as their appetites evaporate. Their beautifully colored bodies will sway in the water and taunt anglers alike as their minds turn to the spawn.

There are several types of bull trout, which include: resident, fluvial, ad-fluvial, and anadromous. Stream resident bulls are those who stay within a single stream throughout their life. They were born in that stream, live in that stream, and spawn again in that very stream. These fish tend to not grow as big, as they don’t move into areas where larger distribution of food can be found. Fluvial bull trout are those who migrate from a larger river system into smaller streams to spawn. These trout will spend most of their time in the main stem of a river system before heading on their migratory journey into the smaller tributaries. These fish are usually much larger than their residential cousins, finding it easier to pack on the pounds hunting the bigger game found in the larger water columns. Adfluvial are the largest bull trout. These bulls overwinter in large bodies of water such as lakes or reservoirs, while living a gluttonous lifestyle. These fish can grow over to 20 pounds and be 35 or more inches in length. They will travel hundreds of miles to their spawning grounds throughout the summer months, in an attempt to quench their insatiable need to reproduce. The last type of bull trout, anadromous, are only found along the western coast of North America. This form of bull trout migrates from natal freshwater streams (where they were born) to feeding habitat at sea. These bull trout are struggling to adapt to changing conditions as their natural habitat is being altered by humans. Dams, logging, and fluctuating water levels have put pressure on this form of bull.

As these beautiful silver creatures begin to change colors like a chameleon, with wonderful yellows, reds, and oranges shining through, so begins their journey to create the next generation of voracious carnivores. Their beauty is only second to their endless appetite for big meals which leads to their overwhelming size. Bull trout are an enigma to many anglers, who often only get a glimpse of them as they attack a fish unlucky enough to be hooked near where they lurk. They travel in pods, which are groups of bulls that migrate up river together. One day you could find yourself catching endless numbers of bulls in a pool where a pod has come to rest, and the next find that deep dark hole devoid of all fish life. Bull trout are very curious creatures and deserve more respect than many anglers give them. Though, at times, they can be easily lured into chasing a fly, and they still represent a fight of a lifetime. Plus, you need to find them first, which is half the battle.

Now that you know a little more about the local bull trout population, it’s important to remember that bull trout are listed as a threatened species under the Endangered Species Act. In many states, like Montana, it is unlawful for an angler to specifically target these trout while fishing. If anglers do by chance accidentally hook them, they need to be released immediately. For areas where bull trout fishing is legal, such as Canada, where I reside, it’s important to remember that bull trout populations were once endangered. People treated bull trout like trash fish, tossing them into the bushes to prevent them from preying upon more sought after trout like cutthroats or rainbows. As the summer drags onto mid to late august, it might be time to put away the big streamers and leave these beasts alone to do their thing. Their energy is best to be used creating the next generation of beautiful trout instead of spending ten minutes on the end of your line. Bull trout take several years to mature, often not spawning until 7 or more years of age. Be a steward for the creatures you love so and think before you fish.