Fishing Small Streams in Yellowstone: Part II, Tactics

Fishing Small Streams in Yellowstone: Part II, Tactics

small stream rainbow trout
Pretty small stream rainbow trout (maybe with a bit of cutthroat genes), typical for size and for beauty.

This is my second post of two in series about fishing small streams in Yellowstone. This part covers tactics.

Small, steep, fast-flowing streams can be daunting to anglers who aren’t used to them. They just look like whitewater torrents, and the many obstacles both in the back cast and ahead make even getting your flies in the water hard at times. The key is breaking the water down: finding places that suit the trout’s needs, no matter how small they are.

What Small Stream Trout Need

  1. Access to food: In small streams, this means current, since the trout generally wait for food to come to them.
  2. Protection from Predators: Small stream trout are easy prey for birds, mink, and so on. As such they need easy access to safe areas. They move out of these areas to feed, but will hold where they can dart back in with a minimum of effort. Two things provide protection in small streams: depth and overhead cover (limbs, branches, angled rocks, and foam). Overhead cover includes most boulders, since they seldom hit the river bottom straight up and down, and most small stream trout can fit in the nooks and crannies where they hit the stream bed.
  3. Water That’s Slow Enough They Don’t Burn all Their Energy Holding Position.

Here are some examples. A stretch of fast, shallow gravel (where most aquatic insects live) offers great access to food, but it’s exposed to predators and would require a fish to swim so hard it would burn all its energy. A shallow pool would offer an easy resting place, but no protection and little food. A deep, slow pool would offer protection and resting water, but little food.

What this means is that trout are looking for areas where all three factors come together. A bit of slow water that’s a little deeper than average (look for water that appears slightly green), just downstream of or surrounded by fast water, with some combination of boulders, logs, overhanging branches, and foam. These spots need not be large. A single eight-inch trout can easily hold in a prime spot the size of a large shoebox.

Your primary job when fishing small streams is to find small pieces of water that fit a trout’s needs, then to fish them individually. The following section provides and example.

Holding Water Breakdown

The following image shows how I would break down a single very good pool on “_____________ Creek.” When you’re fishing small streams in Yellowstone, most spots will be far smaller and more marginal than this one. In fact, the little spot behind the small dark rock marked “Next” above the rapid is a better example: a spot little larger than an end table surrounded by whitewater.

From the position where I took the photo, I would fish the numbered spots in the order they are marked. When fishing small streams in Yellowstone, it’s always a good idea to fish the closest water first. That way, if you catch or spook the fish there, you won’t drag it through the rest of the spot while fighting it, spooking other trout. The overlap in the spots is intentional and something you should follow when approaching a piece of water with numerous holding areas, since the trout will have a different look at your fly or flies depending on where they land. If you landed a dry-dropper combo at the top of Spot 1, a trout sitting right at the top of the spot would not see your nymph since it had not yet sunk, whereas if you cast to the top of Spot 2, that same trout would be able to see and react to the nymph as it reached the bottom of Spot 2, after it had time to sink.

(Aside: I took this pic in late July 2012 and never used it for anything. This is a good example of why you should keep all but your worst snaps.)

breakdown of small stream holding water
Excellent pool on a small stream. Most are smaller. I’ve superimposed boundary lines for the likely holding water and given the order in which I’d fish them.

Spot 1

Spot one is probably the fourth-best or fifth-best spot in the pool. It his slow, as shown by the flattening surface currents, but only fair access to food since it is not near much fast water and there are no surface currents to concentrate remaining food. Moreover, the spot is quite exposed. It’s moderately deep, as shown by the green water, but the cobble-sized rock I’m standing on extends out into the middle of the spot, and rocks that size are too small to tuck under. The best holding water is near the right side of the spot, the area just upstream from the large boulder. You should expect mostly smaller fish when you’re fishing small streams in Yellowstone. Such a fish could tuck under that boulder and still have access to food. I would expect this boulder to hold one fish that would probably take a nymph rather than a dry, unless the fish were very aggressive. Casting to the top of the spot would serve the purpose of helping the nymph sink by the time it reached the boulder.

Spot 2

Spot two is one notch better. It’s still rather shallow due to the cobble rock, but it’s got a bit of foam on the surface. “Foam is home,” and is always worth your time when you’re fishing small streams in Yellowstone or elsewhere. It provides overhead cover and collects dead insects that are easy pickings. It also shows where currents intersect. Current intersections are usually slower than any of the currents themselves. This better access to food and better cover argues for a better and perhaps larger fish. I would expect it to take either a dry or a nymph in the foam running diagonally from top left until just under the “2,” or perhaps in the turbulence from the “2” until the end of the spot.

Spot 3

This is probably the best spot in the hole for numbers and might hold a good fish, too. The current tongue between spot 4 and spots 5-6 crashes right into the corner of the boulder. Some turns off to create spot 5. The rest is slowed and runs parallel to the boulder. That water is likely the deepest in the pool, the rock provides cover, and there will be a lot of food present in that spot because of the way the current funnels along the rock (look at the way the water surface looks like corduroy there).  There’s even some foam, perhaps torn off spot 5 or perhaps formed on its own. This is a large enough and good enough spot it might hold several fish. I would break it into three chunks for casting purposes. I’d first bounce a cast or two off the bend in the rock to the right of the “3” and let it drift out of frame. Next, I’d cast straight left of the “3” where this hole intersects with Spot 4, to see if an aggressive fish was hanging further off the boulder than I’d expect. Finally, I’d cast to the left tip of the triangle where Spots 3-5 converge, so that my drift ran all the way down the rock.

Spot 4

This is probably the worst in the pool. It’s too fast and also rather exposed. That said, it’s green rather than white and has some depth, so it’d be worth a cast or two to see if an aggressive fish has moved into it.

Spot 5

This one might be as good as Spot 3. I doubt it would hold more than one fish, but it might be a good one. In fact, when you see a spot like this when you’re fishing small streams in Yellowstone, bring your A-game. This creek holds rainbow-cutt hybrids, rainbows, cutthroats, and browns, in about that order. I’ve caught 14-15″ browns and cutthroats in spots like #5. I’m not sure if the current is running downstream or backwards here, but either way, the key to approaching this spot would be to keep all of the fly line and most of the leader off the water so that the fly could bob naturally in the probably-swirling foam line running diagonally across the spot. That’s almost certainly where the fish would be. I would cast into one of the currents leading into the foam, probably first the back-current where the current seam splits between spots 3 and 5, then into the overlap between 5-6 near the fast water on the far bank. This would allow my fly or flies to float naturally into the foam. I would expect the eat to be on the dry fly in this spot, and I would expect to have to delay my hookset since a fish with that much foam overhead would probably eat slow and lazy even if it was normal-size. I would expect the best fish in the hole to come from this spot.

Spot 6

Spot 6 would be better if Spot 5 wasn’t there. The spots are close enough together that good-sized fish will want to move under the foam in Spot 5. That said, an aggressive fish might be in Spot 6 since that’s the area where any bugs washing into the area will first be visible.

The Rules for Fishing Small Streams in Yellowstone (and Elsewhere)

The following basic rules apply when fishing small streams in Yellowstone and anywhere else. The more turbulent and broken the water is, the more important they are.

1. Break the Water into Many Small Pieces, Covering Each with Several Short Presentations Before Moving on to the Next

The whole previous section was basically about this. This is the single most important factor when fishing small water. The single worst thing you can do is try to fish a big chunk of water all at once. If you do, the best cast scenario is that the quality of your presentation and your fly looks unnatural due to drag. Since most small stream trout have to work hard for their food and have a short growing season, they will usually eat anything that resembles food. Real bugs don’t drag across the water like motor boats.

2. Make Lots of Short Casts

Since each piece of holding water is small and the currents between them often fast and chaotic, plan to fish at short range and make lot of short, accurate casts. This is the only way of hitting your targets and helps achieve good drifts. How close is close? A rod-length of fly line is often more than enough, even if you’re using a short rod as I suggest in Part I. Two rod-lengths is often too much, and three rod-lengths would be equivalent to casting 80 feet on a big river. Instead of casting farther, walk closer, either in the water or by hopping from boulder to boulder. Don’t worry about spooking the fish. The fast water will mask your approach.

3. Keep Your Drifts Short

As is the cast with short casts and cutting the water into tiny pieces, fishing short drifts will aid you in maintaining good control over your fly. This is largely a function of the chaotic currents you’ll deal with when fishing small streams in Yellowstone. The longer the drift, the more likely it is these currents will start to grab your leader and mess things up. Since a natural drift is far more important than fly pattern on small streams (even more so than on any other fishery), don’t let this happen.

4. Keep Your Line off the Water

Fly lines drag more than leaders in chaotic currents, so keep them off the water. Keeping casts short helps, but so does holding the rod out near shoulder-height and perhaps keeping the rod tip elevated. This invites wind-drag, however. I usually aim to hold the rod basically level or even slightly tip-down, but with my arm high.

5. Be Open to Oddball Casts

Because of various obstructions, you will only rarely be able to make the classic back cast over your dominant shoulder. More often, back casting at odd angles to keep your cast under or above bushes or to set up the forward cast to around rocks or under logs, roll casting, dapping (setting your fly vertically where you want it, without a true cast at all), or ungainly hybrids of all of these will be necessary. It doesn’t matter what your cast looks like as long as it gets your flies where they need to go. This is one reason to fish buoyant dry flies. If they float great, you can drag them through the water and otherwise abuse them and they’ll still float.

6. Try to Fish 90 Degrees Across Currents, When Possible

Let’s backtrack to Spot 3 in the example above. It’s probably the easiest spot to fish in the entire hole. Why? Because I’m standing almost straight across from it. This means that the line between me and my flies will be the “short end of the triangle.” This fact will make everything above except the casting easier, since I’ll be reaching over fewer currents. Getting an approach like this isn’t always possible, but it’s your highest percentage presentation when fishing small streams in Yellowstone.

7. Move Fast

Small stream trout are either going to eat or they won’t. I often tie on a single Coachman Trude and never change pattern when fishing small streams in Yellowstone. The trout in these creeks have a short growing season, basically July-September, that will see them through a long and cold winter, and even in the summer they have to work hard just to make a living. Three to five casts that get where you want them and drift how you want them are sufficient in all but the largest spots. The only one in the example above where I might make as many as ten casts is Spot 3, and as noted I would further subdivide that spot because of its quality, making it in essence three different spots.

small stream angler in Yellowstone.
Fisherman working a small mountain stream in Yellowstone.

The angler above is getting fishing small streams in Yellowstone generally right. He’s fishing the confluence of the foam patch in the upper end of the screen and the faster water in the lower end. The foam patch here is actually very shallow and slow-moving, so it’s not as good as most, but the faster water is deep and dark-bottomed, giving the fish cover. They are basically looking for bugs drifting down in the fast water that get momentarily trapped in the ragged edge of the foam, making them easier prey. I’ve marked the end of his fly line with a red dot (it was hard to see when I resized the pic for online viewing). He’s running about two rod lengths of fly line, and that’s only because the spot is a long one. He’s holding the rod out but generally level to keep as much line as possible off the water, and has positioned himself where he did to make his back cast easier. A 90-degree presentation was impossible due to the steep banks on his side and how visible he’d be if he stood straight below me. In regards to how fast he fished this area, we fished about half a mile of this little creek in about two hours, me guiding and him fishing. We probably spent less than three minutes on this piece of water, and it’s one of the largest chunks of holding water on the creek, hence the picture.


Fishing small streams in Yellowstone offers visitors and locals alike a chance to shed crowds and enjoy low pressure fishing during the heat of the summer. In addition, the tips above will serve you well whether you’re fishing small streams in Yellowstone or any other mountainous area, whether in the Rockies, the Appalachians, or elsewhere in the world. If you’ve got any questions, feel free to contact me. You can also leave your own tips in the comments.

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