The Jefferson River, along with the Madison and Gallatin, is one of the three tributaries that form the Missouri River near Three Forks, MT. The Beaverhead, Big Hole, and Ruby form the Jefferson River near Twin Bridges, MT. One of the larger rivers in the region, Jefferson has over 50 miles of quality trout water which flows through a diverse landscape including canyons and wide-open valleys.
The Jefferson River is one of the least heralded fisheries in Montana as the drought years of the last decade, along with heavy irrigation demands, severely hurt both the trout habitat and populations. Conservation efforts and a reprieve from the drought in recent years has brought the river back to the minds of many anglers. Typically not the river of choice when it comes to finding big numbers of trout, fly fishing the Jefferson is a great option for anglers looking to get away from crowds, enjoy the beautiful scenery, and target larger fish on a guided float trip.
The headwaters of the Jefferson River are a little over an hour’s drive from Bozeman, near Twin Bridges, MT. The upper stretches of the river are considered to have the best trout populations and receive more attention from guides than the rest of the river. There are several outfitters and guide services in Twin Bridges and Dillon that fish the upper river nearly every day, so our guides focus their attention on the middle and lower stretches between Whitehall and Three Forks, Montana The biggest key to success on the Jefferson River is being the first or second boat on the water, so our Bozeman fly fishing guides always head out early when going that way.
Early season, as the waters flows are dropping and clearing following the runoff, is our favorite time of year to fly fish the Jefferson River. Oftentimes, when there is only a foot or two of visibility and the waters are still above the “summer” bank, Jefferson can fish as well as any river in the west. Big streamers and nymphs fished on heavy tippet right against the bank from a drift boat can be deadly on the big browns that are normally very wary the rest of the year. Good flows this time of year give the normally placid river a lot of character in higher flows and always makes for a great time on the water.
Hopper fishing on Jefferson can be “hit or miss” during July and August but is something we like to try every few days with experienced anglers. It’s pretty typical to go away between fish this time of year as lower summer flows tend to concentrate the trout into smaller areas of good holding water. However, the trout that do come up to eat a hopper often do so with authority, run hard, and average in size around 16+”.
Tricos are a small, black Mayfly that hatch in the pre-dawn hours and then come to the water surface late morning in what is described as a “spinner fall.” These hatches are very dense with the spinner fall being the kind of experience you simply have to see to believe. The vast numbers of bugs that end up on the water bring trout to the surface in the late morning and can provide some great “match the hatch” dry fly fishing where we target specific trout as they slowly sip down the spinners.
The Jefferson River is a wild trout fishery so one can expect to catch a wide range of trout sizes throughout the year. There are less fish per mile in the Jefferson than the other blue-ribbon streams in southwest Montana, so the average size of fish tends to be slightly larger. We expect to catch Rainbows that will primarily be in the 16-17” range and fight exceptionally well. Brown Trout are also common throughout the river with the average size being slightly larger than the Rainbows, with some reaching the 25” mark. On a good day, we’ll end with 15 trout in the boat with a dozen or so in the 14-17” range and a few larger ones too. A tough day usually looks more like 3 fish that are each about 16”.