Spring Hatches in the Western US

For most of the US, spring is still a dream that may come true some day.  We long for the warmth of April afternoons, looking for sunscree...

For most of the US, spring is still a dream that may come true some day.  We long for the warmth of April afternoons, looking for sunscreen and great spring trout fishing.  While that is still a few months out, now is the time to prepare.  There are plenty of nice hatches to look forward to, so get that vise out and start tying!

In the western US, we see about 5 major hatches before the "big bugs" come out in May or June and plenty of smaller hatches that are regional or just not prolific enough to make the headlines.  

Blue Wing Olives

We will continue to see Blue Winged Olives on most days, especially when it is cloudy, rainy or otherwise nasty out.  As the days lengthen and the weather improves, we see less and less of them, but they can usually be relied on for an afternoon hatch on cloudy days through March, and as late as late April in the Rockies.  One of the single best days of dry fly fishing I ever saw was a prolonged BWO hatch on the Green River in Utah in late April.   Blue Winged Olives are really a large group of similar insects that can vary in color shades and size,.  I try to have some darker patterns along with some in a brighter green, and others in more pale shades in a #16-20, with a few larger ones just in case.  For example, the Barr's BWO is great, but often time the Barr's Blue Dun is the ticket.

Favorite BWO Nymphs

BH Barr's BWO
BH Micro Mayfly
Mighty Baetis

BWO Thorax - A deadly fly when the hatch is on!

Favorite BWO Dries

BWO Thorax
Parachute BWO
Baetis Cripple

Stoneflies

Early Brown Stone
photo: www.troutnut.com

In most locales, we should see some stoneflies.  Skwalas start to show when we get a few nice days of weather.  It could be early February or as late as late March depending on the location.  On the Deschutes and the Yakima, we usually see them around President's Day.  They don't hatch as thick as Salmonflies, but trout eat them with just as much enthusiasm.

Another stonefly to keep an eye out for is the "Early Brown Stone".  It can usually be found in January and February, and sometimes can be found into April depending on location.  These little mini stones tend to hatch sporadically and in in smaller numbers than their bigger cousins, but even if they are not into the dries, the nymphs are providing adequate food underwater. 

In April and into May, trout should start gorging on a pile of Salmonfly and Golden Stonefly nymphs.  This buffet will keep them busy in between caddis and mayfly hatches, and will provide a large chunk of the calories that they consume in the spring.

Golden Stones signal the start of summer!

The adult Salmonflies and Golden Stones start hatching in May and June in most river systems, and will continue though June.  In some places, the big stones can hatch through July.  We will cover adult salmon and stonefly patterns more in the summer edition...

Because there are stoneflies available as early as January in a lot of river systems, we love fishing stonefly patterns in  the late winter and spring. It is a big food source for fish throughout the first half of the year, and should be a staple of your spring fly box.

Pat's Rubber Leg - Peacock

Favorite Spring Stone Nymphs

Beadhead Micro Stone
Pat's Rubber Legs #10 in: coffee, black, peacock or olive/brown
BH Kaufman's Stone #12
BH Copper John #10 black

Favorite Skwala Dries

Bullet Head Skwala - Solitude
Chubby Chernobyl
Skwala

March Brown Mayflies

March Brown Nymph

photo:  www.troutnut.com

Next is the March Brown Mayfly.  It usually starts hatching about 2-3 weeks after the Skwalas, typically in March and April.  We love this mayfly.  It can produce some nice fish early in the year.

Unlike Blue Winged Olives that are often found in back eddies and softer pockets, March Browns can often be found in riffles, where hungry trout can steadily rise to the adults.  Anglers love fishing riffles.  The cover from the uneven water surface, the fish eating heartily in shallow water; it is what anglers love to see!  March Browns are different species on the East and West coasts, but the basic shape, size and colors are the same.

Favorite March Brown Nymphs

BH March Brown
BH Hare and Copper
BH Hare's Ear

Favorite March Brown Dries

March Brown
Gray Fox
Borcher's Drake

Caddis

A smorgasbord of mayflies and stoneflies will keep trout busy throughout April and into May when we start to see real signs of the impending summer.  The Mother's Day Caddis hatch is often the first time that caddis flies swarm the air and the river.  The little caddis can be as thick of a hatch as you will ever see.  Insects typically hatch in a size #14-16, and can range from grey to dark olive to dark brown, although olive seems to be the most prevalent color.

Mother's Day Caddis - May 2010 - Henry's Fork, ID

The Mothers Day Caddis can go on for weeks, but soon other types of caddis join the party.  The Green Rock Worm is another spring hatch that can be really fun and productive.  It happens later in the spring, often in June.  

Favorite Spring Caddis Pupa

BH Z-Wing Caddis
Green Rock Worm
BH Caddis Pupa

Favorite Spring Caddis Dries

Elk Hair Caddis
Mother's Day Caddis
X-Caddis
Cutter Caddis

This by no means covers all of the hatches you may see on any given river in the west, but is a typical representation of the major hatches that anglers set their calendars to.  The timing of the hatches can vary greatly by location.  Warmer locations in the southwest tend to have earlier hatches, and big rivers in the north have later hatches.  The salmonflies can pop in early May on the Deschutes, but may not hatch on the South Fork of the Snake until July.  All we can do is tie what we can, be prepared to run into varying conditions and hope that everything lines up for a good fishing experience.

Andrew Perrault
-Fishing, usually not catching