By Patrick Straub EBS Fishing Columnist
The skis are stored away, the chairlifts have stopped spinning, and mornings in area campgrounds are chilly and filled with low-hanging campfire smoke. It is legitimately fishing season – but as we experienced early in April, our freestone rivers can succumb to early runoff.
The fish gods have a demented sense of humor – as quickly as our rivers can start fishing well, they can become muddy torrents due to snowmelt. Fishing the Mother’s Day caddis hatch can be equally frustrating.
The fly shops, online outfitters and magazines rave about this annual hatch – this writer is also guilty as charged. Being at the right place at the right time for an early season caddis hatch, like the Mother’s Day hatch, makes up for all of the days watching a muddy river flow past. However, this legendary hatch is unpredictable and doesn’t always occur on or near Mother’s Day, which is May 8 this year.
Here’s some help to find yourself in the right place at the right time.
Be a weather hawk. Explain to your jealous boyfriend or girlfriend that you’re not on Tinder, but instead you’re browsing weather reports for Bozeman, Big Sky, Livingston, and Ennis. Fishable conditions on area rivers and hatching caddis often ride a very thin line of cooperation.
The ideal scenario for water clarity and caddis are daytime highs in the 50s or 60s, and nighttime lows below 40 F. Once the daytime highs hit 70 degrees, the risk of muddy water increases. I like the 60-30 rule: daytime highs in the 60s and nighttime lows in the 30s.
Geek out on stream flows. Working with numbers and charts has never been my thing, but this time of year I’m all about them. If I watch the weather closely, I watch stream flows even closer. As air temps rise and fall, stream flows follow suit. While a gradual shift in either direction is fine, a major rise in flows will cause a river to be muddy.
The ideal scenario is a gradual drop in stream flow, which is caused by cooler temps stalling the snowmelt. Then a gradual increase in air temps increases water temperatures and spurs the caddis to hatch. Stream flow charts illustrate this – study them, because they will be your best friend until mid-May, when runoff usually commences in earnest.
Don’t fall for the hatch too hard. Just as quickly as things can work in your favor, they can work against you. You can watch the weather and stream flows as much as you want, but planning is an upstream battle. For example, the weather and stream flow forecasts could be in your favor on a Friday, but by Saturday afternoon or Sunday morning, temps could rise and you’re fishing muddy water. Roll with what the fish gods give you. And if you’re lucky you can:
Catch the caddis bug. Hatches don’t plan themselves for weekend days. Given the small window of fishable conditions, be prepared to call in sick. Like a powder day, fishing the Mother’s Day caddis hatch means you need to forego responsibility at a moment’s notice. My best spring caddis days all came when I should have been doing something else – but I was sure glad I didn’t listen to reason.
Have a plan B. If you’re planning to fish the Mother’s Day caddis hatch on the Yellowstone or Lower Madison, make backup plans. The Upper Madison is always a good option, as well as the Paradise Valley spring creeks. For every year that I’ve hit the hatch right, there are three years where the stars just didn’t align.
Springtime caddis hatches can be worth the hype. They can also be an exercise in angling frustration. How you choose to handle the adversity is up to you – you can leave this area for cleaner waters like the Bighorn and Missouri rivers with the masses, or roll the dice and stay local. It’s like sitting through a hurricane. If you end up in the eye, it’s legendary. Fortunately, the Mother’s Day caddis hatch is safer than a hurricane.
Pat Straub is the author of six books, including “The Frugal Fly Fisher,” “Montana On The Fly,” and “Everything You Always Wanted to Know About Fly Fishing.” He and his wife own Gallatin River Guides in Big Sky, he is co-director of the Montana Fishing Guide School, and co-owns a guide service on the Missouri River.