Skwala Hatch Attracts Anglers
The sun was shining on the Bitterroot Valley as the man stepped out of the SUV with Oregon plates. He’d pulled into a gravel lot at the head of a trail cutting through a collection of pine trees to the banks of the Bitterroot River.
The man opened the back door of the car and out jumped his black lab. The dog was excited, running and jumping, enjoying the fine weather. Next, the man pulled his fly rod from the backseat. It was already strung and he was already wearing his waders and vest. The last thing he did before climbing the fence and disappearing down the trail was stuff a pair of Bud Lights into his vest.
He was not alone.
Around every turn, four or five people could be found casting their lines into the water. It was the first week of March. The sharp cold of winter was just beginning to dull, and the local fly anglers were beginning to stir.
“There are a lot of people trying to get out on the water,” said Jay Dixon, a long-time fly-fishing guide in the Bitterroot Valley and owner of Dixon Adventures, an outfitting company based in Florence.
All of this isn’t because of the weather. All of this is because of one ugly bug: the skwala stonefly.
Skwalas are enormous bugs, growing to about an inch in length. When viewed from above they are nearly indiscernible from a piece of tree bark. Closer examination reveals the short brown legs and greenish-yellow body hiding beneath their brown wing case.
To University of Montana entomologist Diana Six, that doesn’t sound ugly.
“They’re cute!” she said with a laugh. “They are more colorful than a lot of our Montana bugs.”
As a nymph— the larval form of an insect—the skwala is mostly brown and has distinct patterns on its body. Nymphs swim from the bottom of the river to the shore, where they hatch into adults. Once they hatch skwalas can be seen floating down the river—the real reason so many anglers rush to the Bitterroot River this time of year.
“People are out trying to get some of the first dry-fly fishing of the year,” Dixon said.
Dry flies imitate insects that are visible on the water. Anglers love dry-fly fishing because fish rise to the surface to take the flies into their mouth, usually with an emphatic splash or acrobatic leap. The skwala hatch on the Bitterroot River allows fishermen to chase this thrill early in the season.
However, it’s not the easiest hatch to predict and fish.
“It seems like skwalas are really picky,” Six said. Water temperatures determine when bugs begin hatching. Every insect has a different set of ideal hatching temperatures. This is where Six sees the skwala’s pickiness.
“They have very narrow boundaries,” she added.
For skwala nymphs to begin swimming to shore, water temperatures need to be between 38 and 40 degrees. Once they reach shore, they wait for another set of water temperatures—this time between 40 and 48 degrees—to actually hatch into adults.
Water temperatures increase throughout the warm and sunny days of early spring, providing conditions for late afternoon or early evening hatches. However, warm temperatures are never a certainty in the spring. Even the warmest days are often punctuated by freezing nights, making daytime sunshine even more important to the skwala hatch.
Dixon agrees. He called the skwalas photophilic, meaning they are very active in sunlight—as are another species Dixon knows quite well.
“The anglers also get active,” he said.
Not only do locals dust off their gear and throw flies into the water, but people come from as far away as Seattle to fish this hatch. And that also means money to the Missoula area.
A 2011 study by the University of Montana’s Institute for Tourism and Recreation Research reported over $3 million spent in Missoula County by non-residents on licensing and outfitting services. Much of that money is a direct result of prolific hatches like the skwala.
Because these hatches attract many out-of-staters, local fly shops thrive.
“Bugs bring people to town, and their first logical stop is the fly shop,” said Zach Scott, a guide at the Missoulian Angler Fly Shop, adding that major hatches like the skwala are essential to a fly shop’s survival.
Inside the Missoulian Angler, fly tyers and anglers look to fill their early season needs. One man searched anxiously for olive furry foam, a material he uses to tie the bodies of his skwala imitations.
He didn’t find it.
“We can’t keep it on the shelves,” Scott lamented as he shook his head and shrugged, adding that a lot of other materials used to tie skwala patterns are also selling out, as well as skwala flies tied in-shop by the Missoulian Angler staff.
Eric Henslin, a guide for Hamilton-based Western Flies and Guides, has also noticed a major increase in business. It is no surprise. He marks the skwala hatch as the beginning of the fly-fishing year.
“It really kicks off our season,” Henslin said. “And we start with a bang.”
That bang has grown louder and louder.
When the 42-year-old Dixon began his career just over 20 years ago, the hatch was a relatively well kept secret. But, by the early 2000s, magazines and other media outlets began exposing the grandeur of the hatch.
“We were … disgruntled,” Dixon said of the initial reaction of he and his colleagues to the notoriety the hatch began to gain. “Don’t give up our secret.”
Dixon added that with the recent explosion of social media, the hatch has now caught even more attention, saying, “It’s really kind of exacerbated the whole thing.”
But the attention sure hasn’t dissuaded this longtime angler and guide. He doesn’t seem to care much anymore about others knowing the secret. He still loves to go out and fish.
“For me, it’s about getting out there and having fun.”
And, as the skwalas begin to hatch, fun is exactly what it will be.