Boulder River Rainbow Trout
Photo Courtesy Steven Lamb
Copyright 2019 James Marsh
Fly Fishing On The Boulder River In
The Boulder River starts in the Absoraka-Beartooth
Wilderness in the Gallatin National forest. It's a tributary
of the Yellowstone River. This river has a wide diversity
of water types from its headwaters down to its lower
valley section. The lower section flows through open
areas of land near the town of Big Timber.

From the Boulder River headwaters downstream for
about twenty miles, the river consist mostly of fast,
pocket water with lots of plunges, fast rapids, riffles and
runs with some pools. This section has mostly rainbow
and cutthroat trout. Lower downstream it begins to fall
on a  lower decline and the water slows down to a more
moderate speed with longer sections of riffles with larger
and deeper pools.

It flows over the hundred foot high water falls at the
Natural Bridge State Monument and then begins to slow
down even more as it flows through agricultural land.
The section below the falls downstream for about ten
miles flows through private property without any access.  
Farther downstream it picks up the water from the East
Boulder River at the Forks and begins to speed up to
some extend through more open and wider areas of
pocket water.

The lower sections of the river contains some very nice
size rainbow and brown trout ranging from about ten to
twenty inches. Much of the fishing done below the falls is
done on a drift boat or raft. The water above the falls is
very difficult to float in anything but a kayak. We don't
suggest it at all for fishing purposes. Below the falls,
downstream of the confluence of the East Boulder River
the river can be fished from a boat, but the upper
section is still quite fast. The lower section of the river
slows down and can be fished from any type of drift boat.

Fly fishing the Boulder River is as good as most any
stream in the United States. It is just surrounded with
many more fine trout streams most of which have been
published much more than the Boulder due to its lack of
commercial establishments. It is one of Angie and I's
favorite Montana streams. We highly recommend it.

The season is the general Montana Season
Springtime is only good prior to the runoff
Summertime is the best time for fly fishing the Boulder
Early Fall season is usually excellent

Season closes 11/31/13
Type of Stream

Brown Trout (Wild)
Rainbow Trout (Wild)
Cutthroat Trout (Native)

Small - Medium

South West Montana

Nearest Towns
Big Timber

3rd Sat. May - Nov 30th


Special Regulations

Non-Resident License
State of Montana

National Weather Service Link
Boulder River Montana
Free Shipping Continental U. S.
100% Satisfaction Guaranteed
Boulder River Fishing Report:
11/07/13 Customer reporting Boulder River
fishing good using our PF
Olive nymphs. Catching several trout per
day. Brown trout spawning.
(Bottom Of Page)
Boulder River Fishing
Updated: 10/
05/14/14 Season closed until the third
Saturday in May of 2014. Check back next
week for our first fishing report for the new
05/21/14 The general trout fishing season
is now open but the stream levels are high
due to the warmer weather.
05/28/14 Stream levels still high and will
be that way for the next few days.
06/11/14 Stream levels are in much better
conditions but still a little high. It is getting
warmer and insects are hatching. We have
no reports from anyone fishing.;
06/18/14 One report from an angler
catching a few trout and buying flies. The
water is still cold and few hatches have
started. It is muddy downstream of West
Boulder, but clearing in the headwaters.
USGS Real-time Stream Flow Data:
Boulder River at Big Timber
07/10/14 The stream levels are down and
fishing is really good. Several stoneflies and
mayflies are hatching along with some
caddisflies. Three good reports from
customers fishing this past week.
07/23/14 More good fishing reports from
the past week. Levels are good and plenty
of insects are hatching.
07/30/14 No reports came in from last
week but the water levels are good and the
weather is excellent.
08/13/14 Stream levels and other conditions
are great and lots of trout are being caught.
09/03/14 Fishing was good until the water
levels came up. Give it a few days to subside.
09/24/14 Customers are reporting great fishing
with plenty of hatches still taking place.
October Caddis should start any time now.
10/08/14 The water has been high at times
but we have received some very good reports
for the past two week.
10/15/14 Stream levels have been on the
high side for the past few days. No reports
of fish being caught.
10/22/14 One report from a local angler
catching a few trout on  our BWO nymphs.
10/29/14 Another good report from a
customer who fished the Boulder this past
week. The water was a little high but
streamers worked (our
Brown Sculpin)
11/05/14 No reports from last week but
conditions are currently better.
11/30/14 Season Closes tomorrow
04/28/15 Give us a call or send us and
email to help you plan your next Boulder
River fly fishing trip
05/26/15 The season opened last Saturday
with some high water levels. Keep a check
from the link on your upper left.
06/09/15 Still in runoff but falling.
07/07/15 Runoff is over and the stream back
in good condition. Lots of insects are
hatching including stoneflies, mayflies and
08/04/15 Excellent stream levels, good hatches
of PMDS, Little Yellow stones, and Spotted
Sedges . Terrestrials working.
08/11/15 We are getting reports of up to 50
rainbows a day. Great conditions. It will be
warmer this coming week.
08/18/15 Lower water levels has slowed the
"catching" down some. It is going to be much
cooler this coming weekend & that will help.
08/25/15 No reports from anglers fishing but
the conditions are the same - low water levels,
some hatches but warming back up.
09/01/15 It is cooling off and that will improve
the fishing opportunity. It will change the
aquatic insects that are hatching, so stay in
touch. The river is just a little low but otherwise
09/08/15 The river is flowing at a normal and
good level for this time of the year and
wading is easy. There are still some hatches
but terrestrials are also a good option.
09/15/15 The river is on the way up with rain
forecast through Thursday. It will be much
cooler and that should help big time.
09/22/15 The river was high for a day or two
but back down to a good, normal level. Great
weather and there are still some hatches.
09/29/15 Great conditions exist right now.
The weather is going to be cooler this coming
week. October Caddis should begin to hatch.
10/07/15 One good report came in this past
week. Customer caught several nice
rainbows and a large brown on our October
Caddis pupa.
10/13/15 Lots of October Caddis are
hatching and trout are taking the adult egg
layers from the surface. Brown trout are
Boulder River Map
10/20/15 The Boulder has produced well for
one of our customers this past week. October
Caddis are at the peak of their hatch.
10/27/15 Stream levels still in good shape
for wading. Blue-winged Olives are hatching
good and in two sizes, 20 and 16.
11/03/15 The water temperature is going to
take a plunge this week. Hatches will mostly
be BWOs and midges.
11/10/15 The stream levels are fine and the
water still warm enough for trout to feed
good. No reports from the past week.
11/17/15 Lots of snow forecast for this week
but mild temperatures. BWOs and midges
will hatch under these conditions. Should be
11/24/15 There's a storm warning in effect
through Thanksgiving day. We didn't receive
any reports from anyone fishing this past
12/01/15 Should be a good week for fly
fishing the Boulder. Highs in the forties
and no snow or rain. Fish midges in
tandem and the Brown Sculpin streamer
and you should catch trout.
12/08/15 The weather is going to take a big
swing this week. There is rain and snow
forecast every day. Winter stoneflies are
12/15/15 The river water temperature in
down in the high thirties with ice around
the banks. It is going to be tough but
midges could work.
12/22/15 The water temperature is from 39
degrees down to freezing. The conditions are
tough but not impossible.
12/29/15 The water is about 37 degrees and
below in some areas. We recommend you
choose another destination at this time.
01/05/16 It is going to be a little warmer this
week with lots of snow. You may be able to
catch some trout on the lowest section.
01/13/16 There is a lot of snow in the
forecast everyday. Fish the lowest section
with midges or a nearby tailwater would be
even better.
01/19/16 The highest water temperature to
be found on the Boulder is 35 degrees. There
is lots of slush ice and ice along the banks.
01/26/16 The water is still too cold for you to
have any reasonable chance to catch trout on
the Boulder. Now is a good time to plan your
next trip. We can help you with that:
02/02/16 Same story, second verse. The
warmest water in the Boulder river is only
reaching the mid thirties, a couple degrees
above freezing. Select a nearby tailwater.
02/09/16 The weather is going to be a little
warmer this coming week but there is far too
much ice to melt and we still don't recommend
fishing on the Boulder River yet.
02/16/16 The levels are fine but the water still
very cold. You might try cream midges or winter
stonefly nymphs in the lower elevations.
02/23/16 The warmer weather has melted a lot
of snow and ice in the Boulder river watershed
and this has the water very cold and stained.
03/01/16 The water has cleared up some and
gotten a degree or two warmer but it is still cold.
Another week of good weather is ahead with
little snow, so maybe things will change soon.
03/08/16 The stream is still flowing at a good
level and clear, but there is a lot of snow
changing later to rain in the forecast this
coming week. The river is sure to rise some.
03/15/16 Good stream levels still exist but it is
back to midges as the only real choice. The
water temp. is only in the high thirties.
03/22/16 The river is at a good level, but it is
cold water. The warm spell is over and there is
snow in the forecast every day.
03/29/16 The stream level is normal but the
water is very cold, at 37 degrees in the lower
part of the river. Midges are about the only
choice. Fish slow water current seams..
04/05/16 The Boulder is in as good of shape
as possible at this time of the year. It will be
warming up and melting snow this week.
Sculpin streamers will work.
04/12/16 The river is currently blown out and
there is more rain coming through Friday. It
will be a few days clearing and dropping.
04/19/16 The stream level is still high and the
water stained. This is unlikely to change with
more warm weather and rain coming this week.
04/26/16 The Boulder is very high and stained
badly. There is rain forecast everyday and this
is unlikely to change. Keep a check on it.
05/03/16 Stream levels are still high but
clearer and getting warmer. The Mother's day
caddisfly hatch is a few days away at the most.
05/10/16 The river is high and dirty and likely
will remain that way for the coming week.
There is little to no opportunity for fishing.
05/17/16 The stream level is still a little high but
dropping. There's more rain and it may again
go back up. It is gradually getting warmer.
05/24/16 The river is still high from spring runoff
and lots of rain and will be in this condition for
the next several days.
05/31/16 The flows are high and most likely will
get higher due to the warmer weather in the
forecast. Right now it can be fished, not waded.
06/07/16 The river is flowing at 3360 cfs at 5.96
feet or blown out. This is from both rain and
runoff and should continue all week.
06/14/16 The stream levels has dropped some
but it is still high and very dingy. The runoff isn't
over yet, so expect some more high water.
06/21/16 Stream levels are way down and
getting into good shape. Lots of stoneflies,
Salmonflies and Goldens, are hatching.
06/28/16 The flows are down to 653 cfs at Big
Timber, which is a good level. Lots of insects
are hatching and conditions very good.
07/05/16 Stream levels are down in good
shape and wading possible many places. Lots
of insects are hatching and fish being caught.
07/12/16 The stream levels are still down,
offering plenty of places to wade safely. There
are mega Golden stoneflies and llittle Yellow
stonefly hatches, as will as many other insects.
07/19/16 Stream levels are way down and
wading possible about anywhere. We are
getting some very good reports from
customers. Lots of insects continue to hatch.
07/26/16 The river is still low and very warm,
especially on the middle and lower ends.
There is some rain forecast the next two or
three days, and it is needed.
08/02/16 The river is running a little below
normal but there is some rain in the forecast.
Lots of hatches are taking place. Fish the
upper and middle sections, early and late.
08/09/16 The Boulder River is under Hoot Owl
restrictions from Natural Bridge to the
confluence of the Yellowstone River. You
cannot fish after 2:00PM.
08/16/16 Still under Hoot Owl restrictions. Fish
early mornings with sculpin streamers.
08/23/16 There is an EMERGENCY CLOSURE
RIVER and all of its associated tributaries
starting 8/19/2016. Boulder Creek is closed.
08/30/16 Still closed.
09/06/16 The closure associated with the
Yellowstone River has been dropped and the
river reopened for fishing. The stream level and
weather forecast looks good for the coming week.
09/13/16 The stream is flowing a little low but
otherwise, in good shape in all sections. BWOs
are starting to hatch good. Terrestrials are
working good.
09/20/16 The stream is still a little low but it is
raining and will continue all week. October
caddis and Mahogany duns are hatching.
09/27/16 The stream levels are running just a
little below normal. There are plenty insects
hatching and fish being caught.
10/04/16 Good conditions exist with BWO and
October caddis hatching good. Brown trout are
entering the pre-spawn mode.
10/12/16 We had a good report from a customer
this past week. He caught a 24 inch brown trout
on our Brown sculpin. Good BWO hatches.
10/18/16 The river is just a little high right now
and tough or impossible to wade in most places.
It is falling and there's little rain forecast.
10/25/16 Stream levels have been good and
about normal but it is on the way up some.
Blue-winged olive hatches are going good.
11/01/16 Stream levels dropped some last week
but are back up to high to fish. Watch the levels.
Otherwise, everything is still in good shape.
11/08/16 Stream levels are still high, too high to
wade safely. Give it another day or two to fall.
11/15/16 Still too high to wade and turning
much colder. Cream Midges and small BWO
nymphs. Brown sculpin streamers will work good.
11/22/16 Stream levels are still up high enough
that it is unsafe to wade most sections. The
water temperature is in the low forties.
11/29/16 Fishing will be tough due to very cold
weather and snow. Highs will not be over
freezing. Water temperature in the high 30's.
03/28/17 The season is over. Send us an email
and let us help you plan the 2017 season.
05/09/17 It is just about a month until the new
season begins. Send us an email and let us
help you plan that first trip.
05/16/17 The season begins this coming
weekend. The stream levels are a little high
right now, but it could be fished.
05/23/17 The season opened with stream
levels a little high, but we didn't receive any
reports. Runoff conditions haven't yet started.
05/30/17 The flows are at 4110 cfs, and that's
very high. The runoff is underway and likely to
continue for the next several days.
06/07/17 The stream is still flowing at 2450 cfs
at 5.23 feet. This is still far too high to fish. It is
also heavily stained.
06/20/17 The runoff is still full-blown with flows
over 3000 cfs. All you can do is stay in touch.
We will keep you informed of conditions.
06/27/17 The stream flows are at 2540 cfs at
5.3 feet, or way to high and still in full runoff
mode. It is usually over by the first week of July
but could be later.
07/03/17 The flows are still 1960 cfs at 4.84 ft,
or way to high to fish. Runoff is still going
strong but starting to fall.
07/11/17 Down to 1060 cfs and 3.98 ft, and can
be fished successfully. Salmonflies are still
hatching along with PMDs and other insects.
07/18/17 The flows are at 750 cfs at 3.57 ft, or
in good shape with clear water. There are lots
of hatches. The salmonflies are done but
Goldens and drakes and PMDs are hatching
very good.
07/25/17 The flow are down to 340 cfs, making
wading easy and safe most anywhere. Good
reports are coming in. Lots of insects are
hatching. Conditions are very good.
08/01/17 The stream is in good condition in
all sections with good numbers of trout being
caught. There are lots of hatches taking place.
08/08/17 Good conditions exist in all
respects. We are getting some good reports.
Lots of hatches and good stream levels.
08/15/17 Now, is a great time to be fishing
the river. Stream levels are low and allowing
good wading opportunity and there are still
plenty of hatches taking place.
08/22/17 Conditions are excellent. There are
still some good hatches and Carpenter ants,
Japanese Beetles and hoppers are also
working good.
08/29/17 Good conditions continue, with good
stream levels for wading and some nice hatches
taking place. Terrestrials are working as well but
don't use them if a hatch is occurring.
09/05/17 Stream levels are low and wading
easy anywhere but be careful not to spook the
trout. Stay low and as hidden as possible. We
continue to get good reports.
09/12/17 Stream levels are still low but should
come up soon. There is rain in the forecast
about every day this coming week. Conditions
are still good, just stay hidden from the trout.
09/19/17 The levels are currently okay but on
the way up. There is rain or snow in the
forecast everyday this coming week. October
caddis will start to hatch soon.
09/26/17 The river is in good shape with good
levels and some hatches. So far, hoppers are
still working. Brown sculpin should catch the
brown trout that are moving around looking
for spawning water.
10/03/17 Stream levels are just a little above
normal and wading safe with caution most
places. BWOs, Mah. Duns and Oct. Caddis.
10/10/17 The stream levels are still a little
above normal and the water a little colder.
Brown trout are spawning and Pre-spawn.
10/17/17 The river is in good shape in all
sections. The water temperature is down some
but still in very good shape. Midges and
Blue-winged olives represent the most
important hatches.
10/24/17 Anglers are mostly locals and they
are catching good numbers of trout including
some large ones. Conditions are very good.
11/01/17 The water temperature is down to
the low forties. Midges are the most important
insects to imitate. Snow is forecast everyday
this coming week.
11/15/17 Only two more weeks of the season
is open. Good numbers of big trout are being
caught mostly on Sculpin streamers. Midges
are hatching good.
11/23/17 Season ends the 30th. Send us an
email and let us help you plan a 2018 trip.
11/30/17 The season ends today. Send us an
email for assistance in planning a trip in 2018.
05/12/18 Only a short time left until the
season opens. The season opens the 3rd
Sat. of May. You can send us an email and
let us help you plan that next trip to the
06/02/18 The season opened to a blown out
river. It is current flowing at 3620 cfs at 6.23 ft.
2000 cfs is strong current, 1500 getting okay.
06/09/18 The flows are at 3590 cfs at 6.21 ft.,
still far to high to fish. Keep in touch.
06/09/18 Flows are down from last week to
2820 cfs but that is still blown out and too high
to fish. Hopefully, it will end soon.
06/23/18 The flows are still 3020 cfs, or higher
than most year peaks. You need it down to
1200 or so. A big snow pack this year.
06/30/18 The flows are down to 2670 cfs, but
still too high to wade or fish. It is falling.
07/07/18 The flows are down to 2170 cfs at
5.6 ft, but that's still a little too high to wade. It
can be fished from a drift boat or raft where
legal. There are lots of hatches taking place.
07/14/18 The river is getting in good shape
but still a little high. There are multiple
hatches taking place including the big
07/21/18 Excellent conditions exist. Good
levels and lots of hatching insects. Send us
an email for a fly list:
07/28/18 The stream levels are in good
shape and wading safe and easy with
caution. Good hatches are occurring. All
sections are in good shape.
08/04/18 The stream is in good shape, with
good hatches, and lots of trout being
caught. The middle and headwaters are
doing best, and lower river okay, but a little
08/18/18 The stream levels are normal and
lots of trout are being caught. There are lots
of hatches and all sections of the river are in
good shape with good numbers of trout
being caught.
08/25/18 The stream is still in good shape
with stream levels just a little above normal.
There are some good hatches taking place
and good numbers of trout are being caught.
09/01/18 The stream level is down to a
normal level and lots of trout are being
caught. Terrestrials are working good. PMDs,
Spotted and Little sister caddis, little Yellow
stoneflies and other hatches are taking
place. .
09/08/18 The stream is in good shape,
flowing just a little above normal.
Terrestrials are working good and there's
still some good hatches taking place.
09/17/18 The river is still in very good
shape with good stream levels. The cooler
weather is helping and lots of trout are
being caught. There are good hatches and
streamers and terrestrials are working.
1. Email us (
with the dates you will be fishing this
stream and we will send you a list of our
fly suggestions. Please allow up to 24
hours for a response.

2. Call us 800-594-4726 and we will help
you decide which flies you need.

3. Email us (
with a budget for flies and we will select
them to match the budget and get them to
you in time for your fly fishing trip.

All orders are shipped free in the
U. S. Orders of less than $100 are sent
regular first class mail. Orders of $100 or
more are shipped via Priority Mail.  
09/25/18 The river is in good shape. Stream
levels are still fine. There are still some
good hatches taking place and lots of trout
being caught.
10/02/18 Conditions are still good. Stream
levels are normal and there are still some
good hatches taking place.
10/09/18 The stream levels are about
normal and the river has good hatches of
Spotted sedges, October caddis, BWOs and
others. Sculpin streamer will get the larger
size trout.
10/19/18 The stream is in great shape with
good levels. The water is colder averaging
about 46 degrees. Good BWO hatches are
taking place.
11/09/18 The stream levels are in good
shape but the water is getting too cold in
the middle and upper sections. BWOs and
Midges are hatching. Fish the lower section.
12/26/18 Season is closed. Send us an
email for help planning your next year's
06/16/19 The river is currently blown out
from Spring runoff. Levels are far to high
to fish. Keep in touch. We will keep you
informed as to the status.
06/25/19 The river has dropped down a lot
but still high, too high to fish good in our
opion. Keep in touch and we will keep you
07/02/19 The stream is still too high to
wade safely. It should fall on out very soon.
07/09/19 The river is still a little high but
can be waded in some places with caution.
There are lots of hatching insects including
the big stoneflies.
07/16/19 The river is in good shape in all
respects with lots of trout being caught.
There are some good hatches taking place.
08/02/19 The river is a little above normal
but in good shape with wading safe with
caution most places. There are lots of
insects hatching and our customers are
catching good numbers of trout.
08/11/19 The river is in good shape
flowing just a litle above normal level. Lots
of hatches are coming off and lots of trout
are being caught.
08/19/19 The stream levels are in good
shape and the water clear. There are
good hatches and our customers are
reporting some good catches.
09/05/19 The stream levels are normal and
the water clear. We received three good
reports from customers the past few days.
Good hatches are taking place and our
terrestrial patterns are also working.
09/15/19 The stream is higher than
normal but we are still getting some good
reports. The cooler weather ahead will be
a big help.
09/27/19 The river is well above normal
level but fine for drift boats. We are still
getting good reports. The weather is
cooling off and that will help.
10/10/19 The river is much cooler with
water temps about 47. New hatches of
October Caddis, lots of BWOs and others.
Getting good reports from customers.
10/24/19 Stream levels are still above
normal,but in good shape. The weather is
cooler with a chance of snow Saturday,
Monday and Tuesday. The cooler weather  
is helping several good hatches that are
taking place.