The annual Mother’s Day Caddis hatch is one of the most anticipated events here in Southwest Montana. While it may not be quite as famous as the Salmon Fly hatch, the fishing can be every bit as good, if not even better. The sheer number of bugs that take to the air during the peak of the hatch is astounding. The oscillating clouds of bugs over the water can be mesmerizing, but the splashy rises of trout will quickly snap you out of it. The Yellowstone and Madison Rivers have the premier Mother’s Day hatches in our area, so let’s take a look at when to expect the hatch and some strategies to maximize your success on these rivers. Yellowstone River Timing is everything with this hatch, and we need several variables to come together at once for productive fishing on the Yellowstone. The heaviest hatch on the ‘Stone will take place as the water temperature begins to creep above 50 degrees, which typically happens sometime around the first week of May. This is pushing right up on the start of runoff, so the water clarity will be the determining factor as to how good the fishing is during the hatch. The Yellowstone will come in and out of fishable shape multiple times each spring, so anglers cross their fingers that the hatch hits during an “in” period.
If water clarity is good, expect about a week of heavy hatch activity. This hatch can literally explode overnight, going from just a few bugs to a full scale caddis blizzard. Again, the first week of May is average but it all depends on water temperatures. There are several tributaries in and just below the town of Livingston, MT that dump mud in the spring, so the fishing is concentrated from town upstream into Paradise Valley. While there are a few spots to wade, the Yellowstone is a large river and fishing from a drift boat or raft is preferred. When the hatch is extremely heavy you may have the opportunity to fish dries in the morning, but afternoon and evening fishing is most consistent.
The Mother’s Day Caddis is best imitated by a tan, light brown, or olive caddis pattern in a #14. Traditional patterns like an Elk Hair Caddis or X-Caddis work well, but my favorite is some version of a Parachute Caddis. I like the way these flies ride in the water, and the indicator post makes the fly easier to see from the boat. I will usually fish an emerger or pupae pattern as a dropper off my dry fly as well. Trout can become very focused on one particular stage of insect during a hatch, so I like show them more than one at a time. When the fishing is on, there will be no mystery as to where to present your fly. The vast majority of risers will be along the bank, so you can cruise down and cast to fish as you spot them. Blind fishing your caddis along the banks can be productive as well. Trout feel safety in numbers, so they will often pod up during big hatches. When I find one of these pods, I like to park the boat down below and get out to target them on foot. Madison River Because the Madison River is a tailwater, the Caddis blitz here is more predictable and very unlikely to be washed out by muddy water. The Mother’s Day hatch takes place on what locals refer to as the “Lower” Madison. This is the stretch of water below Ennis Lake. Just below Ennis Lake lies Beartrap Canyon, an extremely rugged 8 miles of whitewater. The best caddis fishing takes place just as the river exits the canyon, from Warm Springs access down to Black’s Ford access. The river is surrounded by almost 100% public land in this stretch and it is easy to wade or float.
The timing is basically the same here, with the bugs really getting going as the water hits 50-52 degrees during the first week of May. We can fish the hatch for longer on the Madison because the water clarity stays good most of May. Cherry Creek is a significant tributary in this stretch that can add mud to the river, but this can be avoided by heading upstream. There is also a boat ramp at the Cherry Creek confluence, allowing float anglers to take out here. On the Madison, you will find some dry fly fishing during the day, but nymphing will be much more productive. As the sun starts to get lower and finally leaves the water in the evening, the dry fly bite heats up. One big difference on the Madison is that the fish are everywhere, whereas on the Yellowstone they are usually targeting dries along the banks. The Lower Madison is a very shallow river with many weed beds and holes and pockets where fish can hide. While a boat is still nice, this is a great stretch of river to explore on foot. By wading and carefully watching an area, you are likely to spot subtle rises that boat anglers miss as they float by. You will not see any classic deep pools on the Lower Madison, so concentrate on drop offs, current seams, the edges of weed beds, and big boulders in the river. This river can be a bit tricky to read at first, but if you put in your time the areas that hold fish will become more obvious.
For flies, you will need the same bugs as you would on the Yellowstone. An olive or tan caddis in #14 with an emerger as a dropper is my top choice. I like my emerger fairly close to my dry to reduce drag, about a foot is what I use. I also apply floatant to my emerger and dry it when it becomes water logged. I want it floating right in the film in order to look natural to the fish and also to allow me to see the take. The visual take and match the hatch nature of the Mother's Day hatch certainly makes it one of the hi-lights of our Montana fly fishing season!