Where to Find Big Trout | Part Two: The Spillouts

by | Sep 15, 2019 | 18 comments

** This is Part Two of the Where to Find Big Trout series on Troutbitten. This all reads a lot better if you first read Part One. Find it HERE.  **

— — — — — —

Imagine your favorite big fish river. Maybe it’s one with a reputation for growing the big boys, with the parking access worn in and wide open. Or maybe it’s even listed in that book about twenty-five rivers for finding the giants. If you fish one of these places, that’s a good start. So conjure an image in your mind of the best . . . let’s say . . . half mile of that water.

Or maybe your favorite big fish river is a little more secret. Maybe it’s a lot more secret. Maybe you already understand how solitude and low returns can equal big rewards. If the river access starts on the other side of some thick brush, or the parking happens in a one-car slot of cinders off a narrow dusty road, you might have something pretty special. Even the big name rivers harbor places like this somewhere in the watershed. (But I’ve already been through all that.)

READ: Troutbitten | The Secret

Either way, imagine your favorite big fish river. And if you don’t have one yet, stop reading and go fishing. Now think about what’s upstream and downstream of your truck — the whole span of water you can access in a full day on the water. If you’re a float fisherman, well that’s just cheating (kidding), because you might cover fifteen miles of water in one day on a boat.

Anyway, somewhere in that long stretch of river that you’re thinking of, somewhere between the banks and buried below the currents, is a place where big trout are found (almost) predictably.

It’s a Spillout

Riffle. Run. Pool. Riffle. Run. Pool. Repeat.

That’s in the first chapter of every Reading the River 101 course. And in most streams the pattern holds — to some extent. It’s just the way the earth was built and the valleys were carved. Every trout stream alternates between pools, riffles and runs, no matter the size. The pools may be short or the runs may be a little slow, but the pattern is there to be found.

And just downstream of a run, right where it blends into what can fairly be called a flat or a pool . . . is the spillout.

I suppose you can point to a spillout every time a run dumps into the neighboring pool. The feature is always at the transition. But for our purposes — for seeking out big trout — only a small percentage of these spillouts are good targets.

And what is good, Phaedrus?

Riffles and runs are the food factories of a river. Nymphs hatch and grow there. They cling to rocks and homemade shelters while trying not to get washed away. Of course, they’re also picked up by the current and tossed around — and that’s when they’re most available to trout.

It’s the same for baitfish. They feed on small nymphs and know where to find them. And my favorite place to fish a streamer is just off to the side of some of my favorite nymphing runs.

All of that trout food, both small and large, gets washed away and stirred up in a heavy rolling run. So the longer and swifter is the run, the more nymphs and baitfish find themselves in the wrong lane, washed away and maybe a little out of control. So, look for the longest runs — ones with good depth and speed. And then find the spillout below.

Furthermore, look for spillouts that are narrow. Find ones where the main flow is compressed into less than half the width of the river. Gary Borger refers to this as the throat of a pool. Find a narrow throat where the current pushes through and enters the pool. Large rocks, wide shelves or rootsy banks may all force this kind of entrance into a pool, and it makes for a good spillout.

“You look at where you’re going and where you are and it never makes sense, but then you look back at where you’ve been and a pattern seems to emerge.”
Robert M. Pirsig — Zen and the Art of Motorcycle Maintenance.

It may take a while to find a good spillout on a small, high gradient stream. I would not call this a spillout. Think larger. Places like this might harbor big trout, but it’s not nearly as predictable of a setup as a classic spillout where the whole rivers comes together and then dumps into a pool. — Photo by Sammy Chang

Spillouts happen on every size of river, and the elements that make one stand out from the rest hold across the range of sizes. And yet, here’s the difference: a small river may hold just one top-tier trout at the best spillout, while a large river may hold many. It’s another myth of big-trout fishing that only one large fish dominates an area. That’s true sometimes, but when you find a good spillout on a sizable river, it likely holds a handful of top tier fish.

Again, this is not your average setup. There’s something special about the best spillouts, and that’s why one of them probably holds your next Namer.

When you find a prime spillout, fish the whole thing. Big trout are surely in the area, and they could be feeding anywhere: in the rough water that’s right in the middle of the throat, or off to the side where the main seam meets the bubbly backwater. Fish all of it.

But the best and most reliable part for big trout in a spillout is right where the current settles down. So let’s talk about that . . .

The Lip

A run becomes a pool because the riverbed changes. Runs are steep and high gradient — water rushes downstream. But pools have a riverbed that’s flatter and low gradient, with water meandering slowly toward the tailout.

The surface of a run is choppy. Mixed currents and whitewater are the defining features. And we don’t need to see the bottom to understand where the rocks are. We can see the results on the surface. And a good, heavy run has water bumping into a lot of rocks down there. The water pushes up and forces a broken surface.

By contrast, a pool has none of this. Even if the pool is dotted with a rocky bottom, the water is slow enough that the surface doesn’t break up.

First, understand that distinction, and now find the place in the spillout where the water softens — where it settles down. Locate where the run becomes a pool.

Underneath this spot — or just upstream of it — is the lip of the pool. And there’s yer spot, mister.

Here’s a prime spillout. Notice what happens when the water drops over the lip. The top current settles and the bottom currents swirl a bit. — Illustration by Dick Jones

Big trout sit downstream of this lip, waiting to ambush a dizzy and disoriented baitfish or to slide over a few inches and intercept a drifting nymph or dry. Feeding is focused here because piles of trout-food pour through the spillout and over the lip. Trout sit in the softer water on the pool-side of the lip, wasting no energy and taking the easy meal that comes to them. This is a prime lie.

Well, this one’s pretty good . . .

No, it’s probably not.

I’m not saying that every spillout produces magic here. Sure, you should fish all of them, because you might find another big trout hangout mixed in — one of the other zones I’ll address in the rest of this series.

So look for all the variables discussed above, and you’ll find the best spillouts on your water.

But know this: More than anything else, targeting big trout is about reading water. Ask Grobe, (probably the best big-trout angler I know) and he’ll tell you the same thing. Check out the fish Grobe caught last week . . .

Photo by Matt Grobe

That’s a twenty-nine inch rainbow. Sure, we both kinda wish it was a brown trout, but this is a wild river-trout from a watershed unattached to any lake. That’s as real as it gets. And it’s a beast. Did he catch it from a spillout? Grobe won’t tell me.

Zen, and the art of . . .

If you’re lucky, there are a couple prime spillouts in that stretch of water you imagined back in the first paragraph. Go fish them hard. Learn the contours of the bottom and see the river the way a trout sees it. Understand it from the perspective of finding an easy meal and conserving energy. Fish it with whatever flies you work best, and then try the other styles. Cast to every inch of it. Then back up and do it again. Because if this is a big fish river, you’ll find them holding and feeding in a good spillout.

Good luck out there. And fish hard, friends.


This is Part Two of a Troutbitten series on finding big trout. Here is the full series . . .

Part One — Big, Bigger, Biggest
Part Two — The Spillouts
Part Three — The Special Buckets
Part Four — The Permanent Structure


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Enjoy the day.
Domenick Swentosky


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Domenick Swentosky

Central Pennsylvania

Hi. I’m a father of two young boys, a husband, author, fly fishing guide and a musician. I fish for wild brown trout in the cool limestone waters of Central Pennsylvania year round. This is my home, and I love it. Friends. Family. And the river.

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  1. Now that I’ve read this I need to fish after work at my favorite spillout!

      • It’s overcast today so I have to. I can’t stand looking out of my office window. Doesn’t help that the river is literally in view.

  2. Good stuff here. I do have a request however: Could you continue your gear articles? Specifically, I am interested in rain gear for both winter and summer. Rain gear that doesn’t send me to the bank for a loan. And rain gear that doesn’t turn into a mini sauna. As with all of them, I got a lot out of the other articles and participated in buying some of the equipment mentioned. You’ve really done a lot to helping me refine my game and make fishing enjoyable. Thanks much.

    • Hi Jim,

      Thanks. I really don’t consider Troutbitten a gear review site. I do gear reviews sparingly. There are so many articles that I want to write, but there’s only room for a couple new articles a week. I’ll probably continue on the same pace of one gear review about every 6 weeks.

      However, once the shop launches, I will have a gear section with links to all of my favorite gear and the reasons why it’s my favorite. That might help too.

      Feel free to email me. I’m happy to give you my opinion on any gear choices, really.



  3. Another outstanding read!! Thanks Dom

  4. I know of at least 6 areas on the rivers I fish that fall into your lip description. I think I’m gona Mayer’s Mini Leech them. Is it Friday yet?

    • Nice. Good luck, Louie.

  5. Pirsig, huh? I loved his book, did you just read it? It’s not referenced often, is it? It took me forever to get through, but I’m glad I did. Pirsig was an interesting dude, brilliant, schizophrenic. He died a couple of years ago. He’s like Salinger in that they each wrote one influental, acclaimed book, and that was kinda it.

    • That book has been a favorite of mine for a long time. It goes in my fishing bag on long trips.


  6. My backyard one of the best rivers in the states, Williamson River Oregon 15 – 18 lbs redband not out of the question 5 to 8lbs all day long. However sometimes size 18 3 or 4 lb tippit better be on your game. Has been catch and release for a few years now has made a big difference.. All Native Americans can fish all year round any bait any size no limit! Everybody else catch and release all redband rainbows keep 1 brown – brook trout (invasive species) no limit

  7. Come try your hand

    • Sounds kind of aggressive. I’m not much into fishing competitions.


  8. Great continuation of the big fish series, Dom. I agree 100% with it. Interestingly, I caught my personal best wild brown trout a few months back. It was a namer. In SEPA even! But it was caught in the most epic spillout in this fishery. I put so many casts into this big, complex pool over the years knowing full well that there had to be a monster in there. When I finally caught this monster… it was on a streamer and at the backend of the pool. As you pointed out… start at these lips where and be sure to fish around, them, too. Can’t wait for the next part!

  9. From the butt of my fly rod, I marked 16, 18, 20 and 22 inches. I then wrapped each mark with copper wire from my fly tying kit and sealed them with clear expoy. That way I can easily measure my fish.

    • Nice. Good idea. I have marks on my net, which makes things even easier.


  10. Phaedrus!

    Aside from your “how-to” articles, I applaud your writing ability for well-placed references.


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Domenick Swentosky

Central Pennsylvania

Hi. I’m a father of two young boys, a husband, author, fly fishing guide and a musician. I fish for wild brown trout in the cool limestone waters of Central Pennsylvania year round. This is my home, and I love it. Friends. Family. And the river.

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