Spring Hatches by Scott Sanchez
Spring fishing - Scott Sanchez
On area waters, pre-runoff may be the best
match-the-hatch dry-fly fishing of the year. Other
advantages of early-season fishing are the solitude and the
trout’s relative naivety. They are less wary of larger
tippets and flies than fish that have been cast to for a
For wade anglers, the lower flows make these rivers
more manageable and it’s easy to move below the high-water
marks. Depending on snowpack and air temperatures, you can
float later in the spring just before runoff, but make sure
your takeout isn’t gated or blocked by snow. Also, in lower
flows fish congregate in slow, deep areas and feed in pods.
Consider planning shorter floats than you would in the
summer and concentrate on fishing to these pods.
Timing early-season fishing can vary with altitude and
weather patterns. In general, the spring season lasts from
mid-February through mid-April or mid–May when runoff
begins. The weather can vary from 50 degrees F. to brisk,
snowy, windy days. Dress in layers to stay comfortable.
Most spring fishing revolves around banker’s hours.
Drink coffee, eat breakfast, tie flies, or run errands, and
then head to the water. Radiant heat is important to water
temperatures, hatches, and fish activity, and the best
fishing is usually in the afternoon on relatively warm and
overcast days. Don’t be afraid to go out if it’s snowing or
softly raining, light precipitation bothers anglers more
than the trout.
Midges hatch through winter and consistently in spring. As
February days become warmer and longer, there is increased
invertebrate and trout activity. Initially, nymph fishing
with a pattern like a Zebra Midge in #16-20 is the most
successful technique. Super long tippets help get better
drifts and a deeper one. A Euro nymph type leader is good
for this. Yarn indicators are more sensitive to subtle
takes. Although I have never found red naturals, at times,
red pupae patterns work well.
As the season progresses and temperatures rise,
consistent dry-fly fishing begins. Concentrations of rising
fish are a welcome sight after a long winter of frozen
waters and nymph fishing. Look for trout eating midges in
slow, deep currents. Trout expend less energy in these
areas than faster, summer lies, and midge activity seems to
be heavier in these flows. These areas also accumulate
insects pushed into slack water areas by spring winds and
currents. Inside corners, back eddies, slow troughs, and
tailouts hold the most insects and fish. Some trout move
into very shallow water to take advantage of this food
source, but the largest ones will be closer to the comfort
of deeper water. It takes a watchful eye to spot subtle
Midge clusters, parachute midge emergers, and black F
Flies work well. A midge pupa six inches below a dry is
good for “bulging” fish. Make sure you don’t fish the pupa
too deep; it may drift below the fish where they won’t see
it. If a fish is feeding below the surface, you will a back
not a nose.
Foaming back eddies can hold pods of fish, but they
constantly move. As currents shift the foam’s position, the
fish move with it to follow the collected food and to keep
a roof over their heads. These fish are tough to catch, but
they are often large. It is difficult to keep flies
floating in foam and I recommend cluster patterns that are
easy to see like my MX Midge Cluster or Hi Vis Griffiths.
Midges can hatch with other insects. Baetis and small,
black stoneflies frequently emerge during this time, and as
the weather warms, they become more important. Rainbow
trout get more active prior to spawning and can be caught
in riffles and runs as they feed before they spawn.
As spring rolls on and temperatures increase, small
stoneflies will hatch with midges and it is easy to
overlook them. Stoneflies are not as widespread as midges,
but fish key on them and they can be locally important.
The small, brown/black stoneflies hatch between
January and May, though they are most often seen crawling
on snowy streamside banks. Consequently, a nickname for
them is “snowflies.”
Another spring stonefly revered by anglers is the
Skwala. This olive-brown insect hatches between March and
May, but usually peaks around late March and mid-April, and
is best imitated with #10-12 patterns. Sometimes it doesn’t
happen until runoff. Don’t expect Skwalas to hatch in huge
numbers. You may see only a few adults along bankside
vegetation but know that fish are keyed on them.
When fishing stonefly nymphs, look for riffle sections
followed by slow, deep pools. Stonefly nymphs prefer rocky,
riffle areas of streams and are often dislodged in faster
currents and drift downstream until they regain their
footing, presenting a perfect feeding opportunity for
Stonefly nymphs crawl out of the water onto rocks and
vegetation to emerge. This can draw fish into the shallows,
so be sure to look before stepping into the water in case
fish are feeding close to the banks. Dark Stone Biot Bugs,
and Pheasant Tails are good patterns.
Stoneflies are as clumsy flying as they are swimming
and often fall into the water. Look for fish feeding on
adults falling from bankside vegetation or females
depositing their eggs. Black Caddis patterns, and adult
midge patterns are good dry flies. As with many stones,
sunshine doesn’t seem to bother them.
Baetis – Blue Winged Olives
Around the end of March Baetis appear. The hatches are
widespread with flies in the #16-18 range that vary from
gray to olive and colors in between. Generally, overcast
days produce the largest hatches but once the hatch gets
going, sunlight doesn’t seem to slow it down. Riffles,
inside corners, and tailouts seem to hold the most fish.
Most afternoon Baetis hatches are preceded by midges
and continue until dark. Nymph fishing is productive before
a hatch starts. Size #16-18 beadhead Baetis nymphs,
Beadhead Pheasant Tails, and March Brown Biot Bugs are my
Baetis nymphs are good swimmers and active emergers.
Swing a nymph or a soft hackle to mimic their rise to the
surface. When fish are feeding on adults, I switch to a
parachute Blue-winged Olive pattern like an Adams.
Sometimes when fishing to pods, the first fish can be easy,
but after this you may need to fish more imitative patterns
and finer leaders. If you get refusals on a parachute, an
olive Sparkle Dun, Everything Emerger, or Quigley Cripple
are good bets. I have also had great luck dead-drifting and
slowly swinging a soft hackle. Since overcast conditions
and Baetis hatches go together, expect a glare on the river
and use black or hot-pink wings on your patterns to help
you follow the fly.
Fishing a #14 parachute with a smaller beadhead Baetis
or Pheasant Tail is a good bet and provides more flotation
and visibility. As with midges, don’t fish the nymph too
deep. The Yellowstone and lower Henry’s Fork have
particularly good Baetis fishing.
The Mother’s Day caddis hatch is probably the most famous
Yellowstone area spring hatch and justifiably so. The
number of Brachycentrus, or Grannom Caddis, is astounding
and the fish gorge themselves. This insect is endemic
across the West.
It is usually a mad race between runoff and the hatch.
The best conditions are when it is warm enough for the bugs
to hatch but not so much that the river floods. Some years
the fishing is great for three days while other years it
In the mornings, prior to adult activity, a Glass
House Caddis, a Prince Nymph, or any cased caddis imitation
will fool fish feeding on drifting larvae. The olive glass
bead on the Glass House Caddis is a good imitation of the
natural’s body, acts as an attractor, and makes it visible
to the fish.
Work the riffle water. Brachycentrus often attach
their cases to rocks or plants in medium to fast currents.
A pupa below a large dry, like an olive or brown
Convertible, is a good way to search the water. While there
may be adult caddis in the bushes, the best dry-fly fishing
isn’t until emergence or egg laying puts adults on the
water. Depending on the temperature, emergence is in either
mid-morning or mid-afternoon.
Egg laying is primarily an early-evening event.
Patterns like Dennis’ Sparkle Caddis, Peacock Caddis, Olive
Elk-hair Caddis, and Sanchez Foam Wing Caddis in #14-16 are
good flies. At times a Coachman Trude are highly visible
flies that you can pick out from the rafts of naturals. My
theory is the orange tippet tag on the Trude may be
mistaken for an egg sac. It may be the trigger that causes
the trout to take the fly instead of the natural.
Everything Emergers or X-Caddis are perfect for
emerging pupae and work throughout the hatch. Soft hackles
or wet flies swung down and across in runs and tail-outs
can be deadly and are realistic imitations of emerging
pupae or egg-laying adults. On years when the hatch is
short lived, larger flies and attractors work well, but
when the hatch lasts for a while, fish get selective.
March Browns usually start appearing in mid-April and
vary in quantity from year to year. The nymphs are clingers
and eat the diatoms on the rocks. Prior to emergence, the
nymphs migrate from the riffles to water with a slower
current. This is the best time to fish nymphs since many
are swept from the rocks and tumble helplessly downstream.
After emerging, the duns float for several feet until
their wings are dry enough for takeoff. If the air is damp
or cold, expect the duns to ride on the water even longer
and the trout to be looking up for an easy meal.
Trout seem to go out their way to eat March Browns. A
#12-14 March Brown Parachute or Parachute Hare’s Ear works
as well as any dry, while a Hare’s-ear Nymph is a great
imitation of the nymph. Fish the dry flies on a dead drift,
but like the Baetis, March Browns are active emergers, and
swinging a nymph at the end of a dead drift is worthwhile.
It can be fun to fish light rods, but I like to use an 8½-
to 9-foot, 4- or 5-weight rod for most of my spring
fishing. The length helps with mending, and the heavier
weight helps with spring winds, especially when nymphing or
fishing streamers. In spring wind, I sometimes us my
6-weight. Nine- to 10-foot leaders with 4X or 5X tippet is
adequate for most of the fishing.
Scott Sanchez is a manager at JD High Country Outfitters.
He is a columnist for American Angler Magazine and wrote
the books; Introduction to Salt water Fly Tying, A New
Generation of Trout Flies and The Never Ending Stream. He
contributed the Teton Park chapter of The 25 Best National
Parks to Flyfish