Big Hole River – August 2023

A lot has been written in 2023 about the health of the Big Hole River in Southwest Montana. And none of it was encouraging to the anglers who love the tannin-stained waters and craggy hills of the Big Hole River. We had read the story of the Zombie Trout in the New York Times, so I think Tim was a little surprised when I suggested we sneak off for a few days to fish the Big Hole.

It was mid-August. The Big Hole River was under hoot-owl restrictions, so fishing from 2 pm to midnight was prohibited. Hoot-owl restrictions occur in Montana when water temperatures exceed 73 degrees for three consecutive days; however, this is a general guideline. Other factors, such as water flows and stream conditions, and newer regulations can affect when hoot-owl restrictions are placed on a body of water.

We love the Big Hole Valley almost as much as we love the fishing, so the plan was to fish in the mornings and explore in the afternoons.

Fish Trap Fishing Access & Campground

While working for the Silver Bow Club in Divide a few years back, we stopped to fish at Fish Trap, hoping to grab a few photos for their website. I lucked into a large brown trout on a size 18 Gray CDC Caddis, and ever since we have wanted to spend more time fishing there. 

Fish Trap Creek tumbles off the Continental Divide, flowing southeast to join the Big Hole River at the fishing access. The trout and grayling lay in the feeding lanes, enjoying the cold, oxygenated water.

We packed the camper, stowed the fly rods and Water Master, put our dog, Belle, in the truck, and set out for the Big Hole. As luck would have it, Montana FWP lifted the hoot-owl restrictions on the river that day. This was going to be a great trip!

Frosty Big Hole River at Fish Trap Campground

Frosty Big Hole River at Fish Trap Campground

Storm Approach Fish Trap Campground Big Hole River

Storm Approach in the Big Hole Valley

About the Big Hole River

The Big Hole begins near the Beaverhead Mountains, whose heights separate Montana from Idaho. It begins its 153-mile journey to join the Beaverhead and Ruby River to form the Jefferson River at Skinner Lake. It then flows towards the hay meadows of the Big Hole Valley, cutting a brushy green line through ranchlands and Big Sky vistas. 

The upper river is small and often brush-choked. Fishing access is limited to bridge crossings and select spots. Cold creeks such as the Mussigbrod, Steel, and the West Fork of the Big Hole join the Big Hole near Wisdom, increasing the stream flow.

 Downstream from Wisdom toward Divide, there are numerous fishing accesses with boat launches for float fishing. The river above Divide is best floated in spring and early summer when river flows are higher. 

Above Divide, the Big Hole leaves the valley and flows through tight canyons. In this mid-section the river often stays cooler in the dog-days of summer. Here, the river is a series of riffles and deep pools from Dewey to Glen. 

From Glen to Twin Bridges, the river flows again into wide-open ranch lands, where the water succumbs to evaporation and irrigation needs. 

Big Hole Fishes

The Big Hole is home to many species of trout. Rainbows, browns, and brook trout all can be caught on a good day on the river. Mountain whitefish are plentiful, which can be a good thing on a slow fishing day. But my favorite fish to catch on the Big Hole is the fluvial Arctic Grayling. These fish are unique as they are the only remaining river-dwelling grayling native to the lower 48 states.

Grayling have a beautiful iridescent dorsal fin and readily take dry flies. Their bodies are solid and flanked with soft scales of silver and purplish pink. You’ll find grayling in the upper river primarily but I have caught them downstream near Maiden Rock Fishing Access near Divide. We found their numbers plentiful at Fish Trap.

Big Hole River Grayling

Big Hole River Fluvial Arctic Grayling

Grayling caught in the Big Hole River

Grayling caught in the Big Hole River

Holy Trico Hatch, Batman!

Excited for fishing, we got up early only to find a light frost on everything. Sparkling in the sunlight the grasses and bushes sparkled in the morning sun. Pour another cup of coffee; the day needed to warm up a bit. 

It took a while for the sun to rise over the hill enough to cast its warming light onto the river. But when it did, magic happened. Clouds of tricos filled the air and covered the water. 

Plump grayling and eager brook trout gulped at the bounty while birds flew and darted overheard feasting on the small mayfly. For nearly two hours, the river was alive with action. But as the sun grew higher in the sky and the warmth of the August day set in, the bugs waned, and the action drew to a close.


This trip was dry fly fishing or nothing. Not because we’re dry fly snobs, well Tim is, but because the river was a big conveyor belt of seasonal algae. The blobs of algae got on your line, on your hook, on your boots, everything. It seemed much worse during the day but not as bad in the early morning. Fishing with nymphs and streamers was out of the question. 


Trico Hatch on the Big Hole River

Trico Hatch on the Big Hole River

Trico Spinners on the water at Fish Trap Fish Access

Trico Spinners on the water at Fish Trap Fish Access

Map of the Big Hole River at Fish Trap Fishing Access

Wisdom, Montana

For us, an important part of a fishing trip is the cool thing you do when you’re not fishing. On this trip, we fell in love with the small town of Wisdom. Originally the Big Hole was named the Wisdom River by Lewis and Clark, and this small town of 138 souls was named for the river.

From Wisdom, look north, northeast at the peaks of the Anacondas, southwest at the Beaverheads, and due east at the Pioneer Mountains. Ranching is the primary way of life here. 

There is a small grocery store, gas pumps, and a post office. The Wisdom School serves students from kindergarten to 8th grade with only one teacher, as the school’s total enrollment is generally less than 10. 

Like most Montana towns, there’s a bar, and Wisdom had two! On our first night, we enjoyed a pizza at the Antler Saloon. A young family was tending the bar and cooking pizza while the owner was recovering from a medical procedure. The young kids served customers and learned how to prepare pizza while adults served cold beer. 

We ate dinner at Fetty’s Cafe on our next trip into town. A celebration of life for a cherished resident was going on, and the entire downtown was filled with people remembering and coming together to celebrate the life of a neighbor. There are not many places like Wisdom on this earth anymore. We felt privileged to experience such a great American small town.  

Horses and mules in downtown Wisdom Montana

Horses and Mules in downtown Wisdom, Montana

Tim enjoying a beer at the Antler Saloon in Wisdom Montana

Tim Enjoying a Beer at the Antler Saloon in Wisdom, MT

Wisdom Welcomes You

Wisdom Welcomes You

Beavertail Slide and Hay Bales near Wisdom mt

Beavertail Slide and Hay Bales

Flies That Worked For Us

It’s always wise to check in with the local experts. Here’s what we used during our trip in mid-August.

  • Tricos (dries, spinners)
  • CDC Caddis (gray bodies)
  • Hoppers
  • Chubby’s
  • Purple Haze

Local Experts

Great Divide Fly Shop in Divide and the Sunrise Fly Shop in Melrose are the two shops we frequent the most. They offer shuttles, guided trips, and river-specific flies. Both are small, quality shops with people behind the counter who like to talk fishing. 

Both are conveniently located just off I-15, stop in to pick up flies or hire a shuttle before heading upstream.

 Video – Fishing the Big Hole River in August

Lightning Crashes Over the Big Hole River in Montana

Lightning Crashes Over the Big Hole River

Nearby Fly Fishing Waters

It’s always fun to explore nearby waters in Southwest Montana. So, if you have more than just a couple of days to fish, here are some nearby (Montana nearby) rivers and lakes worthy of a drive.

  • Wise River
  • Beaverhead River
  • Poindexter Slough in Dillon
  • Grasshopper Creek
  • Mussigbrod Lake
  • Pintler Lake

The Necessities

Our picks for fishing information, food, and places to camp.

If You Go

Here are a few tips if you go.

  • There is spotty to no cell service from Divide Bridge upstream to the headwaters. Plan ahead.
  • Gasoline. Get some before you head upstream from Divide in Melrose. Or, if you have enough gas to get to Wisdom, get some there. Keep an eye on your fuel gauge.
  • Food. Again, prepare ahead of time by bringing food or planning to eat in Wise River or Wisdom. And be mindful of closing times.
  • In August, there is a chance the Big Hole River above Divide could be on hoot-owl regulations or, worse, closed entirely if the summer is hot and dry. Plan and call the local experts.

Side Trips

Fishing is fun, but in such a special part of the world, it’s good to take a day or two and look around. Here you’ll find a battlefield, places to dig for crystals, and amazing mountain scenery.


Big Hole River Foundation

The Big Hole River Foundation, according to their website, is a science-based organization that works to protect the Big Hole River watershed through water quality monitoring, education outreach, and advocacy on behalf of its unique culture, fisheries, and wildlife.

Founded in 1988 to protect the river and ecosystem as well as the communities and people the river touches. 

Fishing Guidebooks

Go with knowledge! We keep guidebooks in the camper and the state atlas in all of our rigs. If you’re serious about fishing, here’s our recommended reading for this water.

*The link takes you to Amazon where you can read more about the titles and purchase the guidebooks if you choose. We do receive a small portion of the sale for providing the link which helps to support this site. We appreciate your support!

Subscribe and Learn About More Cool Places to Fly Fish

Recieve our latest blog post direct to your inbox