The Starting Lineup – 3 Flies You MUST Have for the Month of March

brianchilbert
38 minutes ago
4 min read

If there’s one thing we preach this time of year at Colorado River Outfitters, it’s this: March is go-time.

Big fish, empty river corridors, and some of the most consistent hatch-driven fishing of the entire year—it simply doesn’t get much better.

But success in March isn’t about carrying hundreds of flies. It’s about confidence in a dialed, proven system.

CRO guide and Montana Fly Company signature fly designer Brian Hilbert keeps it simple with a deadly 3-fly lineup that consistently produces across the Colorado, Roaring Fork, and Eagle Rivers.

This is it:

Zebra Midge – Size 16
Daysaver Midge – Size 18
Daysaver Baetis – Size 20

Let’s break down why these flies work, how to rig them, and exactly when to fish each one.

Midge hatches in March are often dense. Here are piles of midge shucks along the bank.

Understanding March Hatches

Before we get into the rig, you need to understand what’s happening underwater.

Spring Midges (Morning to Early Afternoon)

Midges dominate early in the day and we mean dominate.

Active from late morning (around 10:30–11:00am)
Peak hatch often mid-day
Fish key heavily on larvae and pupae
Sizes range from 18–14, often larger than winter midges

This is when your Zebra Midge and Daysaver Midge do the heavy lifting.

Blue Wing Olives (Afternoon Game Changer)

As the day warms, especially on cloudy or mild afternoons, BWOs start to show.

Typically begin around 1:00–3:00pm
Fish shift from midges to baetis nymphs and emergers
Size range: 20–18 (with 20 being money)

This is where the Daysaver Baetis takes over.

Brian’s Daysaver Baetis is a proven pattern that fools even the wariest of trout.

The Starting Lineup (Your Go-To 3 Fly Rig)

Brian’s approach is simple, efficient, and incredibly effective:

a 3-fly nymph rig designed to match both midge and BWO cycles throughout the day.

1. Zebra Midge – Size 16 (Your Anchor Fly)

This is your confidence fly and your rig’s foundation.

Why it works:

The Zebra Midge perfectly imitates the larger midge pupae we see in March. That size 16 profile stands out just enough in slightly stained spring water and gets noticed by bigger fish.

How to fish it:

Run it as your point (bottom) fly
The tungsten bead gets it down
Focus on deep runs, buckets, and slower seams

Pro Tip from Brian Hilbert:

“Don’t overthink it, this fly catches fish all day. If you’re not ticking bottom occasionally, try a larger tungsten bead. I’ll typically carry them with a size 2.5mm to 3.5mm.”

2. Daysaver Midge – Size 18 (The Workhorse)

If one fly consistently out-produces in March, it’s this one.

Why it works:

The Daysaver Midge is designed to imitate a wide range of midge pupae, with just enough flash and segmentation to trigger eats in pressured fish.

How to fish it:

Run it as your middle fly
Roughly 14” below your Zebra Midge
Try multiple colors, brown, black, olive and red are all great.

Pro Tip from Brian Hilbert:

“Don’t be afraid to go big. March midges are often a size 16 or even 14.”

3. Daysaver Baetis – Size 20 (The Afternoon Killer)

This is where things get really fun.

Why it works:

As BWOs begin to hatch, trout shift their focus almost instantly. The Daysaver Baetis matches the slender, natural profile of baetis nymphs and emergers perfectly.

How to fish it:

Start the day with one Baetis on the rig if you want, but don’t rely on it early
Around 1:00–2:00pm, switch your rig:
- Drop the midge-heavy setup
- Go with a lighter anchor fly (jig zebra)
- Run two Daysaver Baetis (sizes 20–18 if needed)
Target softer water, edges, and rising fish zones