Frost on their noses, snow clods on their backs and ice on their eyelashes this morning told me that I was probably not going fishing today. My Miniature horses(about 500lbs each), were snorting and bucking when I went to feed them this AM.  Their fur, thick as a wooly mammoths,  is apparently keeping them nice and toasty this winter as they showed no signs of being cold.

…..Me on the other hand was just fine heading back into the house and throwing another log into the wood burning stove.  The burn of the morning air and the sting of cold water splashed onto my exposed skin left me with no desire to slip out and wet a line in my local waters.  6 days since the opener and not one cast to a trout! I must be getting soft.   Next week there might be a warm up.

Lets talk dry flies, hatches, summer stuff. I feel warm already. This week, a friend of mine who makes his way up here once a year along with a gang of other fine and dignified gentlemen asked this question;

Hello! I hope that all is well and you’re prospering in this cold winter (at least, compared to some recent years). I write with a question about sulphur hatches on the Rush. Those of us who gather for “Sulphurpalooza” will soon decide on dates for the 2017 gathering. Each member of the group seems to have a differing opinion about when sulphurs are likely, but my opinion is “we don’t know squat”. Hence, my missive to you…

If you were to peg dates on when sulphurs are at or near their peak in a completely average year, what would those dates be? I fully realize that spring weather and temperatures have a huge impact on dates of emergence. But, we might as well choose dates somewhere near the peak of the “bell-shaped curve”. You are about the only person whose opinion I would have confidence in!

Many thanks for your advice. When the blessed event actually happens, I hope to see you yet again around the dining table and campfire.


Greetings Rex
Great to hear from you. I have completed my 3 days of servitude for the week and now have time to answer you more completely

You have chosen your words carefully to let me know, you know, there are myriad of intertwining variables that must be sorted out in order to answer your question. Your request has been made in a manner to assure me that your “sulphurpalooza brothers” may be a few bricks short of a full data set and your wish is to acquire a more scientific answer to your question. I completely understand.

Here is that answer OR Skip this part and go to directly to the bottom of the page to acquire the “peak sulphur emergence dates in a completely average year”.

According to and in general Malcolm Knopp and Robert Cormier 1997 in Mayflies-An Angler’s Study of Trout Water Ephemeroptera, W. Patrick McCafferty 1981 in Aquatic EntomologyThe Fishermen’s and Ecologists’ Illustrated Guide to Insects and Their Relatives and Gaylord Schanilek 2005 thriller, MAYFLIES of the Driftless Region, the term “sulphur” has been applied to or associated with numerous species of mayflies. Some have been scientifically classified….. Some have been classified, argued about, then reclassified. In the end there are very few laymen who can positively identify these mayflies. Further more, I am not certain entomologists are 100% in agreement on some classifications.

The use of the word sulphur(a common name) has created a goat rodeo in angling lingo and few in the angling world have been able to sort it out. From my experience, this loose fitting term has been used to describe the species; infrequens, inermis, excrucians, needhami, dorothea, invaria and rotunda just to name a few. Some are located in this region, some are not. Some species referred to as sulfurs in this region are probably happy , healthy and scheduled to emerge at their designated time. Some were once here and are now ghosts. Some insect populations only remain in remnant numbers and no longer cause trout to stalk the surface water. For my entire angling history, the word sulphur has been used to describe a number of different mayflies. I have just about given up on discussing it with others because half way through the conversation I realize they are talking about a different insect. SO I LUMP.  In all these years I am not absolutely certain I have made definitive identification of any one bug I call sulphur. I  have found great variability in some of the hatches I have experienced on our local waters. Many of these hatches are compound/complex hatches containing 2 or 3 different species of mayflies. Oh, and lets not forget the yellow craneflies that also have been referred to as sulfurs by so many anglers. SO I LUMP.  To make it simpler. I lump the group  into the light colored flies of summer.

Through my eyes In the last 6-8 years there has been change to the light colored flies of summer or sulfurs, Sulphurs, sulfers, if you will. In the areas where I have fished them for the last 20 years the rivers, insects and populations have changed. Nature is showing off her ability to be dynamic. For years I would watch the development of the Dames Rockets in the valleys and wait for the emergence of the sulfur mayflies. I had no idea these plants were invasive until I popped open this link. These plants were my reminders, my indicators, that dry fly fun was about to begin. In the places where I fish the sulfur imitations, populations have dwindled. The beautiful plants and pleasant fragrance remain in my fondest memories of fishing and place. Although the plants remain, blooming during the same period, the mass flight of mayflies no longer occurs above some of these waters. No longer does the water boil with greedy trout.

Make no mistake, the fish are still there. The habitat looks the same. It is only the massive hatches of insects that for the most part are missing. This fact reminds me that once again change is. I know to expect it. I chill, and move on to find the next honey hole or honey hatch.

We as anglers have expectations. These expectations are rooted in our past experiences. We want definitives and the ability to form patterns and repeat….. With Angling, repeating makes it easier to achieve the same results and create better fish stories.
According to my notes, logs and blogs from the past, the peak emergence times for the sulfurs in a broad sense would be from May 20 through June 20th. In a narrow sense somewhere between the first and second week of June.
A prediction for an emergence of Sulphurs on the Rush or any local river is no longer possible for me to give you. My attempt to hit this hatch or hatches in the last few years has been unpredictable at best after 20 years of reasonable predictability. My sense is that these mayfly populations may be on the low side and may never cycle back,,,, who knows???? Something else may take their place??


Sorry for not being much help. Food, Fire and Fishing is always good when you are around quality people. Let me know when you set the date.