To see stoneflies on steroids getting munched by big-ass fish, you have to experience the USA’s salmonfly (Pteronarcys Californica) hatch. To find out more, we chat to former Protea fly angler Craig ‘Yeti’ Richardson who lives in Idaho these days where he guides on the Henry’s Fork River.

What was your first experience of the salmonfly hatch like?

My first salmonfly experience was on the south fork of the Snake River in Idaho. A WorldCast guide and friend of mine, Zack Barrett, took me out. The flow was higher than anything I had ever seen. Growing up fishing the Vaal River a lot and seeing it in full flood, this river looked higher and faster than anything I had ever seen there. Zack picked out this gigantic #6 foam thing called a Water Walker and told me to get it as close to the bank as possible.

After a few casts a trout that looks like an average Smalblaar trout came up and ate it. I was blown away! Zack rowed to me to a bank and told me to walk through the grass and I’d find some salmonflies. I wasn’t expecting to see so many in the grass but they were everywhere. Picture a fly, the length of your pinky finger that every trout wants to eat.

Er…why is it called a salmon fly? Is it safe to assume that salmon chow them too or is there something else to it? 

I’m not sure why they’re called salmonflies. I’ve asked everyone I know and no one has given me an answer. Spending their entire life in fresh water, salmon won’t go out of their way to eat them but I’m sure a few have over the years. Maybe it’s because the body is salmon pink/orange?

What are the best months for the salmonfly hatch? How long does it last?

It all depends on the area you are in. They need the water temperature to reach 54 degrees Fahrenheit which is 12.22 degrees Celsius. In south east Idaho it normally comes middle to late May for the Henry’s Fork and late June to early July on the South fork. They can run anywhere from a few days to a few weeks depending on how steady the flow of the river is. Big fluctuations will mean the majority get washed away before they can breed. They live for two to four years, so if you have a bad year with bugs getting washed away, chances are the hatch will suck in three years’ time.

Which rivers do you fish when the hatch is on? Do they appear in several states? Where should we rush to when it’s on?

I picked Idaho because of the diverse rivers and massive amounts of public access. So, I would also say Idaho. I fish the Henry’s Fork (the north fork of the Snake River) and the south fork for both the hatches because they happen over different dates. I’m spoilt because I can get up to a month of salmonfly fishing, whereas in other states you’ll be restricted to a week on one river system. Salmonflies are found throughout the west but they are very specific about the type of water and temperatures they can survive and thrive in.

There are constant reports worldwide of how insect populations are plummeting due to pollution, pesticides etc. Eg., more than 40% of insect species are declining and a third are endangered. Any idea what the status of the salmonfly is? Are the hatches as good as ever? Or do resident old-timers see a difference between today’s hatches and those of a few decades back?

Some say it’s better than ever and some say it’s worse. The Henry’s Fork Foundation ( is doing some incredible work documenting everything from flows and snow pack to the density of bugs in each section. Because of their work we have a much better understanding of what needs to happen to improve the bug life which has proved itself with their recent bug report. Salmonflies like water temperatures that don’t fluctuate too much. So water that doesn’t get too hot or too cold through the year makes the difference. A lot of the best salmonfly rivers are tail waters so the water is controlled by a dam.

 Get stuck into the rest of this story and more in issue 33 of The Mission. As always, it’s free.

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