By Chris Lawson
Each Spring I try to visualize what is going through a trout’s mind when the Salmonflies make their appearance on the Henry’s Fork. Starting in late October and November temperatures plummet and the snow starts flying. All the of prolific aquatic hatches that occurred during the summer and fall months have become a thought of the past, the slush ice starts flowing down the river, and our cold blooded friends become sluggish and inactive. Although fishing can be done year round, the winter feeding frenzy is not much of a frenzy anymore.
Then as the water starts to warm in March, the insect hatches begin once again. Baetis and Midges start to appease the fish, followed by the Mother’s Day Caddis in April. Then as May rolls around, I visualize the first Salmonflies that pass by these food depraved trout. This brings to my mind how I feel after having gone an extended period of time without a big meal. It seems like every type of food is appealing. The only thing going on in my find is stuffing my gut, and I wonder if trout have the same mindset.
As the water temperature approaches around 56 degrees, the 3 to 4 year old stonefly nymphs migrate from all corners of the river towards the bank. The nymphs then crawl from the water and attach themselves to rocks, logs, and other structure. They dry themselves for a few hours and emerge into their adult form. The adults can live up to a week and during this time, they find a mate, drop their eggs into the water, and die. In a nutshell, this is the life of a Salmonfly.
One of the biggest questions we are often asked is, “When are the Salmonflies going to hatch on the Henry’s Fork?” The answer is complicated and it is all depends on water temperature. If we have an early spring, the hatch could be weeks earlier than normal. If we have a late spring, the hatch could be weeks later than normal. On normal years the Salmonflies usually start hatching on the lower Henry’s Fork around May 25th.
What does this all mean to our trout friends? Well the first thing the fish see are all the giant stonefly nymphs migrating to the bank. A good thing to consider when timing the Salmonfly hatch is to think like a fish, and ask yourself this question, “How many Big Macs can you cram down your throat?” I could probably fit about two, and then would consider vomiting as an option to relieve myself.
Too many anglers try to time the Salmonfly hatch right in the middle of it. Think of the cheeseburger analogy as the fish are usually so full of the nymphs, that they don’t give much mind to the adults on the surface. The fish you do end up catching are usually vomiting nymphs as you lift them from your net.
Several years ago I remember going on a date that would result in being the first and last date with this particular girl. Strong hatches of Salmonflies were in the Box Canyon, so I took her on a float through Cardiac Canyon, which is just below Lower Mesa Falls on the Henry’s Fork. As I was launching the raft, I saw water explode in front of a rock across the river as a large trout inhaled an adult stone and I knew we were in business. This fine young woman had never fished before, but skill did not matter on this particular day. It didn’t matter where the fly was as she’d slap the fly on the water surface and the fish were on it. She broke one fly off on a rock, and after the line broke the fly fell back in the river. I rowed the boat over and as I was reaching down to pick up the fly; a five pound brown trout beat me to it. It was the most amazing date I have ever been on! It probably was for her as well, after having gigantic adult Salmonflies landing on her face all day, apart from all the fish crap and slime in the boat. She was obviously not “the one” for me, but in my mind it was one of the best dates ever!
Consider this advice when trying to time the Salmonflies and fish behind the hatch! When the Salmonflies are in the Box Canyon…fish Cardiac Canyon. And when the Salmonflies are in the Warm River to Ashton stretch…fish from Ashton to Chester. If you end up arriving after the Salmonflies have come and gone, don’t be disappointed. I say this because the Salmonflies’ close cousin, the Golden Stone, hatches sporadically for weeks afterward, and can be as good as or better than the Salmonfly hatch. When the stars all align, you will never fish a hatch that will bring more monster trout to the fly than the Salmonfly and Golden Stone hatches! Good Luck!