Hatch Chart

Lower Yuba River Hatch Chart –
Or A Hatch Chart for Most Rivers Where You May Roam

Updated November, 2015 – For most of us fly fishers that have attempted to figure out the Lower Yuba River, it’s seasons, it’s bugs, and how to catch the resident rainbows, winter and summer steelhead, I have put together the information that I have gained by many years of fishing the Lower Yuba to create this Lower Yuba River Hatch Chart.

This “Match the Hatch” information, also lists recommended “Flies” to match the bugs found on the river. This will help you solve the many mysteries of the Lower Yuba River. Most of the recommended flies include “Fly Pattern Recipes” so you can tie them yourself.

This hatch chart works for most Northern California river’s and streams. In fact it works for most of Oregon, Washington, Idaho, Montana and Wyoming rivers and streams. Just match the bug, what stage you’re imitating and select the fly and you’re good to go.

So, do your homework, learn to identify the various bugs found on the river, learn to match them with the right flies, and lastly learn when these bugs are available as food for the resident trout and steelhead. You will become a more knowledgeable and successful fly fisher.

Good luck, Clay

Hatch Volume Key


Includes Pattern Recipe.

    The Fly Pattern Index is a complete list of all the recommended flies listed on the Hatch Chart, categorized by Dry Flys, Duns, Emergers/Cripples, Nymphs, Terrestrials, and Other.


Mothers Day Caddis or Spring Caddis or Grannoms

grannom_larva3_300American Grannom is the common name for the Brachycentridae family of caddisfly. I often hear this bug referred to as the “Mothers Day Caddis” and the “Spring Caddis”. It is a hatch that is a welcome fishing opportunity on the Lower Sacramento River typically is late May and April.

The larvae, though cased, often become available to trout due to their common occurrence in stream drift and an unusual rappelling behavior. They drift in large numbers during the day. This activity makes them readily available to feeding trout.


Spotted Sedge Caddis or Summer Caddis

hydropsyche_caddisEach year I always look forward to summer and the hydropscyche caddis hatches. This bug is also commonly referred to as “the summer caddis” the “spotted sedge” or the “net spinning caddis”.

On the Lower Sacramento River the bug takes on a brown or cinnamon cast. On the Lower Yuba River the bugs tend to have a green cast.

The summer evenings will find active feeding fish willing to take caddis emergers and soft hackles.

It is my favorite hatch of the year.


Green Rock Worm

green_larva_300The two larval species most imitated by anglers are Rhyacophila (green caddis or green rockworms) and Dicosmoecus (October caddis). However, the effort may be misplaced because these are not the caddis larvae most consumed by trout.

Rhyacophila are common in extremely fast riffles on medium-sized streams, and while trout sometimes feed heavily on the larvae, it’s usually during the low light conditions near dawn and dusk. Most anglers cast imitatations in water that is too slow or during the wrong times of the day.



Blue Wing Olive (BWO)

bwo_dunThe last few times that I’ve fished the Lower Yuba River I have run into a fairly strong hatch of Blue Wing Olives or BWO’s as we affectionately call them, most of the time I call them “those darned BWO’s”. I’ve seen them coming off, but can I catch one of the fish that are eating them. Forget-about-it. I’m usually rigged up with my 6 weight and nymphs, shot and all when I run into a hatch. So I’m not really set up right to start casting dries, emergers, cripples, or soft hackles like I should be. I usually just stand on the banks and give my buddies a hard time about not being able to hook something. A single person peanut gallery so to speak.

Anyway, this brings me to thinking about what I should be attempting to do when the BWO’s start coming off and start catching some fish instead of laughing at my buddies.


Western March Brown

march_brown_dunEven though the bugs often hatch in godawful weather and us fly fishers have spent many a March afternoon shivering, fishing a run as droplets of cold rain run down the sleeve of our casting arms, we would do it again tomorrow. We’d rather be there suffering and attempting to catch fish. As the month of March begins to wind down the hatches of Blue Wing Olives, “Baetis” and Skwala Stones, “Perlodidae,” have been going on steadily since February a new player shows up. As late March and April arrives the days will typically start warming and the water temperatures will also go up which triggers the March Brown mayfly to start hatching. They can hatch in just about any weather. This is the “Rithrogenia Morrisoni” hatch. This large mayfly is typically an afternoon hatch and once it starts happening you can almost set your watch from it.


Pinkies, Pink Alberts, Pink Ladies or Yellow Quills

Epeorus_DunWhen the PMDs are out and about on the Lower Yuba River there, a pattern that is often mentioned to imitate the duns are “Pinkies”. They work. But the pattern is really a pattern designed to imitate the “Epeorus” mayflies.

These yellow mayflies are important on many streams throughout the West. Here on the Lower Yuba they are around but not in great numbers. Even though it is not a well known insect, the hatches are not prolific and typically don’t occur on flat “technical” water. However, The Epeorus will be found in the swiftest portion of the river, and trout see enough of them to recognize them as food.


Pale Morning Dun or PMDs

pmd_spinner_300On the Lower Yuba River we have been seeing glimpses of what is coming as the season progresses and the temperatures start to warm up. On warmer days there have been PMD’s floating on down the river. It seems to me that in the last couple of years that they are coming earlier in the season then I remember from years ago. Here’s some stuff to get you prepared. Start cleaning those dry lines and organize your fly boxes.

There is a PMD hatch that starts in early spring sometimes as early as February if the weather warms up. This is one of the better hatches on the Lower Yuba. Pale morning duns have everything going for them, large numbers that trigger aggressive surface feeding, fussy enough to offer a challenge, but not so difficult as to be too frustrating.


Pale Evening Dun or PEDs

ped_dun_300Each summer I would fish a run on the Lower Yuba River with caddis emergers and soft hackles in the evenings. We had many days with plenty of fish up in the water column and taking our presentations and running up and down the river. About 45 minutes until dusk we would say “Let’s head for the honey hole”. This was a big back eddy on the way back to the truck. It was a large reversing eddy and each evening right at dusk the PED’s would start coming off. You could tie on a soft hackle and cast it into the main flow headed downstream and it would work its way into the eddy water. Trout would just sit there waiting for the PEDs. You just had to let them take it and lift your rod slowly but deliberately and fish-on. This would go on even after dark and we would be landing fish by headlamp. This became a regular routine. If you haven’t tried this you should.


Slate Drake Mayfly or Great Western Leadwing

isonychia_dun2There seems to be some debate as to what genus that the larger Gray or Slate colored mayflies we come across on the Lower Yuba really are. The concensus is that they are Drakes. Are they the genus Siphlonurus or are they the genus Isonychia? I’m not an entomologist so the best I can do is research.

According to the information in the book “Flyfishers Guide to Northern California” put together by Seth Norman, the chapter authored by our local Ralph Wood, states that they are Gray Drakes or Siphlonurus occidentalis.



tricospinnerTricorythodes or Tricos are members of the crawler group of mayflies. There are nine species of Tricorythodes found in the western states. Only one Tricorythodes minutus is of importance to fly fishers. Tricos are the smallest mayflies in North America, but their hatches and spinner falls are so heavy that the largest trout in the stream will move up to feed on the surface.

Their principal importance is in the spinner stage, when they can coat the surface and get trout to start feeding heavily. The duns, especially the females, can be important during early morning hatches. If you don’t get out early you may be missing the most fishable part of the hatch. The Tricos males and females are slightly different in size and quite different in color.



Skwala Stonefly or Brown Willow Fly

skwala_nymph_300It’s late January and the word on the streets is that the Skwalas are out. It’s time to tie up some big bugs and get ready. The last time I fished the Yuba I picked up a couple of nice fish with a Mercer’s Skwala Nymph. It’s a good one.

The Skwala activity on the Lower Yuba River can start as early as late December and then transitions to “strong” activity beginning mid February and generally lasting until mid April. The Skwala is a very important hatch in that it is the first big meal of the season. Regardless of how many adults there are, the fish know they are there. Fish make their living on eating the predominant insects and food sources of the season.


Little Yellow Stonefly or Yellow Sally

little-yellow_adultThe Lower Yuba River has what I would classify as a minor population of little yellow stoneflies. The Upper Yuba River and the Truckee River has a major population. For this reason getting to know the The Little Yellow Stonefly is a good idea. The “Isoperla” nymphs live in riffles and rocky runs with moderate to fast flows. They are sometimes knocked loose and drift in the current, so a nymph imitation can be sometimes be productive when dead-drifted through riffles and runs.


Golden Stonefly or Golden Stone

golden_adult2Nymphs are large and live in riffles and rocky, bouldery areas with moderate to fast current. They often lose their grip and are taken all year by trout. An appropriate pattern dead-drifted near the bottom is effective. Choose your imitation carefully, however. Many fly shops sell a golden stonefly nymph that is golden in color, but the actual nymph is mottled shades of tan, black, and brown. However, when golden stonefly nymph molt, the new instar can briefly be a much brighter color. It’s possible that trout key in on that brighter shade, which would explain why an imitation works when it seems to be unlike the color of the vast majority of the natural insects.


The Others


3674551257_5a9b1c0cd2When summer rolls around it is time to try a Terrestrial fly pattern. A hopper, beetle, ant or bee. These bugs often get blown into the river and are a big meal for the trout and steelhead. We are indeed in the midst of a terrestrial revolution. Going back to fly fishing’s earliest days, the main attraction has been matching aquatic insect hatches—mayflies, caddis flies, and stoneflies. While never entirely ignored, terrestrials were often an afterthought—something to tie on if nothing else was happening. The reality is that even on great trout streams, fishable hatches aren’t occurring most of the time—especially during the summer. Terrestrials, on the other hand, blunder into streams throughout most of the prime angling season. While hoppers are usually associated with late summer and fall, ants and beetles are active whenever temperatures are warm enough to stoke their metabolism.


Roe or Eggs

Natural_Roe_TroutbeadsFor those of us that live near and fish the Lower Yuba River, we are fortunate to have a run of Chinook Salmon that run up our river to spawn. This typically happens in late August through November or December. This is the fall run. When the salmon start moving up the system the trout and steelhead are right behind them.

They are hungry for the salmon eggs that are being laid in the shallow runs where the salmon dig their redds. When this happens using egg imitations are the best choice for the fly fishers. Using plastic beads or “Troutbeads” are the best.


Clay Hash

Call Clay

(530) 913-1334

Email Clay

Book Your Guided Trips Today

For more information about the FFT Guided Trips or to book a day.

Contact Clay