DIY Guide to Fly Fishing the Big Hole River in Montana

No matter where you call home, there’s no better fly fishing destination than the Big Hole River in Montana.

The Big Hole River flows for 155 miles, starting near the Montana-Idaho border in the Beaverhead Mountains at Skinner Lake. Its final turn takes it into Twin Bridges as it dumps into the Jefferson River.

What begins as a scenic mountain terrain then turns into the Big Hole River Valley which is rich with Montana scenery.

The Big Hole River is one of the only rivers where you can catch rainbow trout, brown trout, cutthroat trout, brook trout and arctic grayling (a “Montana Grand Slam”) in a single day!

About Big Hole River

Rivers mean life, and life means stories. The Big Hole River in southwestern Montana is swimming with stories, from a cowboy-turned-fishing-guide to conservation-minded ranchers to a childhood friend of the noted rascal Evel Knievel. From Epic Montana comes this glimpse of Where the Big Hole River goes and what it means to those who get to know the river.

Best Place to Fish Big Hole River

The Big Hole River has three distinct sections, including the Upper Big Hole River, Big Hole River Canyon, and the lower Big Hole River.

Of the 155 miles of the Big Hole River, the 25-mile stretch that parallels Montana Highway 43 is the most accessible, with both official and unofficial access points throughout. This portion of the river is ideal for the wade fisherman and provides some of the best fishing on the Big Hole River.

With a narrower width, shallower depths, and a calmer current this section is ideal for the angler who loves to wade. Access is the easiest on this 25-mile stretch with numerous access points, which of course lends itself to being heavily populated at peak times of the year. Many of us are willing to sacrifice fishing with many of our peers rather than having to trek down a mountainside to gain access to a less populated portion of the water.

Upper Big Hole River

Image by Mike Cline

The Upper Big Hole River extends from it’s headwaters at Skinner Lake (Headwaters) to the Montana Fishing Access Site at Fish Trap. This reach of the Big Hole River is characterized by a slow moving, high meadow stream and is home to native Fluvial Arctic Grayling.  You will also find a good population of Brook trout here and a smaller population of rainbows and browns.

The Upper Big Hole River is the first section of the river to ice over in the fall and the last section to free of ice in the spring. With slower moving water, numerous grassy islands, and deeply cut banks, this section was made for dry fly fishing.

Big Hole River Canyon

The Big Hole River enters a narrow canyon below the Fishtrap (Mile 81) public access that extends to Melrose, MT. The canyon section of the Big Hole is characterized by boulders and pocket water and is heavily populated with stoneflies (more on that in a moment) and trout!

There are 5 public access sites in the canyon including: Sportsman Park (Mile 78), Dewey/George Grant (Mile 57), Greenwood Bottoms (Mile 57), Powerhouse (Mile 52) and Maidenrock (Mile 48). Rainbow trout outnumber brown trout in the canyon and fish populations are estimated at approximately 3,000 fish per mile.

The steep canyon walls and abundant boulders provide lots of structure and varying water depths.  Fishermen should come prepared with nymphs, streamers and dries and be ready to switch up tactics as conditions merit. With abundant trout, unparalleled scenery and hatches from April through October, the Canyon section of the Big Hole River is a world class trout fishery.

Lower Big Hole River

Image by Mike Cline

The Lower Big Hole River extends from Melrose, MT to the confluence with the Jefferson River in Twin Bridges, MT.  This reach of the Big Hole is characterized by cottonwood bottoms with braided channels and long, slow pools.

There are public access sites at Salmon Fly (Mile 38), Brownes Bridge (Mile 32), Kalsta Bridge (Mile 30), Glen (Mile 25), Notch Bottom (Mile 18), Pennington Bridge (Mile 9), High Road (Mile 2).

Browns dominate rainbow trout in the lower reach of the Big Hole with a trout population of approximately 3,000 fish per mile.

Big Hole River Map and Fishing Access Sites

The Montana Fish & Wildlife Service and the Bureau of Land Management maintain 20 public fishing access sites on the Big Hole River. The location of each Big Hole River access point is shown on the map above. Click the map icon to get information about the facilities available at each access point including the type of boat ramp and whether camping is allowed.

When Is the Best Time to Fish the Big Hole River?

The month of June is the most popular time of year to fly fish the Big Hole River for a couple reasons. First, the water has typically cleared itself of any mud from the spring months. Secondly, the salmon fly hatch has begun. If you are after trophy sized trout, the best method is to use a sink tip line during this hatch bouncing a Kaufmann’s or Brooks Stone in sizes 2-6 along the bottom. You can also use a Bitch Creek Nymph in the same sizes. If you prefer to fish with a dry fly pattern, try the Sofa Pillow in sizes 12-16, yet keep in mind that during this hatch dry flies do not yield as many of the large trout when compared to the nymph patterns.

Big Hole River Hatches

A variety of bugs hatch throughout the year on the Big Hole River.  The most notable hatches start with the Skwallas in early spring, Caddis in May, the famous Salmon fly and Golden stone hatch in June, and tricos and spruce moths in late July to early August. Hoppers abound in late summer and fisherman can throw streamers at aggressive trout all year.

The Big Hole River hatches are typical of a western freestone river and include:

• March – BWO, March Brown
• April – BWO, Skwala, March Brown
• May – Skwala, Caddis
• June – Salmon Fly, Golden Stone, Yellow Sallie, Caddis, PMD, Green Drake
• July – Golden Stone, Yellow Sallie, Caddis PMD, Green Drake,
• August – Hoppers, Trico, Spruce Moth, Caddis
• September – Hoppers, Trico, BWO
• October – BWO, Caddis

Fishing the Big Hole River Skwala Hatch

The first major hatch on the Big Hole River are the Skwala stoneflies and it produces some of the best dry fly fishing of the year. The Skwalla stonefly makes it’s appearance around mid-April in the Big Hole as the ice breaks free and the water warms to between 45-48 degrees.

There are not as many Skwala stoneflies on the Big Hole as Golden Stones or Salmonflies, but there are enough of them to make for some great fly fishing. Dry fly fishing tends to be the best in the tail outs of the runs along undercut banks, pools, and ice shelves.

This is a pre-runoff hatch, so it occurs when the Big Hole is warming up, but does not get so warm that snow starts to melt and blow out the river. Typically the river is still frozen in April above Jerry Creek. The best Skwala activity typically occurs below the town of Melrose on the lower Big Hole River. 

Fishing the Big Hole River Salmonfly Hatch

The most famed hatches on the Big Hole River is the Salmonfly hatch. It is every anglers dream to throw huge dry flies to equally huge (5 pound+) brown trout, which is what you can expect on the Big Hole.

This is truly an exciting time to be on the Big Hole River as the hatch often occurs when the river is raging and coming down from runoff, typically from June 15th to July 1st.

What’s equally remarkable is the the Salmonfly hatch occurs on over 80 miles of of the Big Hole River.  The hatch typically starts on the lower river near Glen then it works it’s way up the river to East Bank as the river warms.

What You’ll Need When You Get There

A 9-foot 5-wt fly rod with floating line is perfect for fishing dry flies and small nymphs on the Big Hole.  For larger nymphs and streamers a 9-foot 6-wt with a sink tip fly line makes life easier.  A tapered 9-foot leader, with tippet size 3X to 6X to match the flies you are throwing, is pretty standard.

Big Hole River Flow Charts

The Big Hole River is not dam controlled and stream flows are subject to change with run-off and precipitation events. It’s important to check the river conditions before heading out to fish. The USGS maintains several stream gauges on the Big Hole River that provide real-time stream flows. If the stream flow varies considerably from the normal conditions (either above or below) you may want to check with an area fly shop to see how the river is fishing.

Big Hole River USGS stream gauges of interest are shown below in order from the upper river to the confluence with Jefferson River.  Click the links provided to locate the gauge on the map above or use the DIY Fly Fishing App to get real-time stream flows from your phone.

Big Hole River below Big Lake Creek at Wisdom, MT

Big Hole River below Mudd Creek near Wisdom, MT

Big Hole River at Maiden Rock near Divide, MT

Big Hole River near Melrose, MT

Big Hole River near Glen, MT

Big Hole River Fishing Reports

There are a number of area fly shops and on-line retailers that publish Big Hole River fishing reports. A few to check out include:

• Sunrise Fly Shop Big Hole River Fishing Report
• Montana Troutfitters Big Hole River Fishing Report
• Orvis Big Hole River Fly Fishing Report
• Frontier Anglers Big Hole River Fishing Report
• Great Divide Outfitters

Big Hole River Closures

The Big Hole River Drought Management Plan designates target river flow and temperature conditions for fish health in five river sections of the Big Hole River. The plan includes voluntary conservation targets for all water users, MFWP fishing restriction criteria, and information tools. Conservation actions are designed support the health of the fishery.

Big Hole River closures are triggered when stream flows drop too low or water temperatures exceed 73F.  Minimum flows that trigger stream closures are listed below by river section.

Fishing Regulations

The Montana Fish, Wildlife and Parks Service implemented the Big Hole River Recreation Rules in 1999 to address public concerns about crowding on the river.  The rules limits the number of float trips outfitters can run each day and prohibit outfitters and non-residents from floating certain sections of the river on certain days.  The rules are in effect the third Saturday in May through Labor Day and are summarized below.

Trip Planning

Traveling to this remote part of the country may seem challenging and costly, yet if you are proactive and start planning early, you can save hundreds of dollars in airfare. The closest major airport is Billings Logan International Airport, which is approximately a four to five hour drive to the Big Hole River using I-90.

As any seasoned traveler can attest, part of the fun of vacations is not only the activity that you traveled to partake in, it is also the sightseeing as you travel to your destination. Use those four to five hours on I-90 to your advantage as you take in the beautiful Montana landscape. You will then take the I-15 exit, travel on it for a short distance, and this will lead you directly to Montana Highway 43 where you will find all the access points to the Big Hole River.

Where to Stay When Fishing the Big Hole River

With a reprieve from the city life in mind, your trip to this portion of Montana will be free of the lights and traffic. So don’t expect all your favorite retailers and restaurants on every street corner. If you will be traveling via a camper, plenty of campsites can be found along the highway as well as off the main drag. If you will be looking for lodging, the city of Wisdom is right off of Montana Highway 43 and offers the traveler some lodging options. Check out the Big Hole Valley site for helpful links to the lodging options not only in Wisdom but in surrounding towns as well.

You are now armed with some of the basics of taking a much needed break from the city life while you cast your fly rod in the beauty of the Big Hole River in Montana. Plan early, save money, and enjoy. You work hard, find the time to unwind and make memories that will last a lifetime.

Looking for more places to fish in Montana? Check out our DIY Guide to the Best Fly Fishing in Montana.