Lamar River YNP
Angie Marsh fishing Lamar River
Copyright 2016 James Marsh
Fly Fishing The Lamar River -
Yellowstone National Park
The Lamar River flows from the Absaroka Mountains in
the Northeast corner of Yellowstone National Park. It has
a total length of forty-three miles but all but eight of them
are inaccessible by road. The Northeast Entrance Road
closely follows the lower thirteen miles up until it flows
into the Yellowstone River. Fly fishing the Lamar River is
not your normal fishing experience, to say the least.

All but the first couple of miles of the lower end of the
upper thirty miles of the Lamar River is actually fished
very little. You either must hike up the stream or go via
horseback. The uppermost part goes through a canyon
on a very steep decline. The trout in the uppermost part
are not as large as they are in the lower part. There are
plenty of them and the action is usually very fast but the
average size cutthroat is larger in the lower section of
the river. They probably average from about nine to
fourteen inches with some going over eighteen inches.

The Lamar Valley is something to behold. It is huge and
contains just about all of the wild animals the park has to
offer including wolves. The river itself is strange in a way
because it can suddenly turn muddy (see thrumbnail
image to your right) from thunderstorms miles upstream.
It is also strange in that dingy water doesn't necessarily
turn the trout fishing off. It seems as if the trout are use
to it although it doesn't happen all that frequently.

You have the options in terms of fishing near others or
getting away from everyone ranging from fishing near
the road to hiking into the back country up to 30 miles
away from the road and/or anywhere in between. Just
remember that your in a true wilderness and have
someone along with you if you venture far up the river. It
isn't a good place to be alone and sprang an ankle.   

Although there are some rainbow trout in the lower end
of the stream near the Yellowstone River, most all the
trout are native Yellowstone Cutthroat Trout. Although
the average size is probably about 12 inches, there are
plenty that are well over 16 inches. We have caught a
few of them over 20.

The season in the Lamar Valley is a short one due to
the elevation of its area of drainage.
The stream doesn't clear and become warm enough to
fish until about the first to the middle of July.
Summertime is by far the best time to fish the Lamar
River. Most of the aquatic insect hatches take place in
the summer months.
Fly fishing the Larmar River can be good in the early
part of the Fall but there will only be a few days before it
becomes too cold to fish.

Fly Fishing Guide to the Lamar River
There are a few things about the Lamar River that are
rather unique and quite different from most other
streams in Yellowstone National Park.
(Click Here To
Type of Stream

Cutthroat Trout
Rainbow Trout
(Wild Trout)


Northwestern Wyoming, YNP

Nearest Towns
Cook City, Montana

Last of May - October


Park License
Yellowstone National Park License

National Weather Service Link

Fly Fishing Guide

Hatches and Flies

Fly Fishing Gear

Stream Flow Data:
Real Time USGS Data
Lamar River, YNP
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Options For Selecting Flies:
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.

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