The Starting Lineup – 3 Fly Patterns You MUST Have for the Month of May Featuring Colorado River Outfitters Guide Paul Killino

May in Colorado is not for the faint of heart. As snowmelt surges down from the high country, rivers like the Colorado, Eagle, and Roaring Fork transform into frothing torrents of cold, sediment-rich water. Anglers new to this time of year often assume that trout are impossible to catch during runoff. But that’s where experience—and the right flies—make all the difference.

To demystify fishing during runoff, we sat down with legendary Colorado River Outfitters guide Paul Killino, a veteran of spring flows and a true master of reading high water. With 30+ years guiding Colorado’s most iconic freestones, Paul knows exactly where trout hide when the rivers rise—and what gets them to eat.

So if you’re gearing up for May, here’s your starting lineup: the 3 must-have fly patterns that belong in every Colorado angler’s box this month, how to fish them together, and the expert insight that only Paul can deliver.

1. Pat’s Rubber Legs – Black, Size 8

The Anchor Fly

If there’s one fly that screams “springtime meal,” it’s the Pat’s Rubber Legs. This chunky stonefly imitation is a staple in the West, but it earns MVP status in May.

Why it works: During runoff, larger stoneflies like the salmonfly and golden stone become active, tumbling loose from fast-moving edges. Trout key in on these easy, protein-packed snacks as they hug the bottom looking for slow seams and soft pockets.

According to Paul:

“When the water’s off color and moving fast, fish can’t afford to be picky. Pat’s Rubber Legs carries a large profile, it’s visible, and it holds weight. It’s your battering ram for punching through the current.”

How to fish it: Use the Pat’s as your point fly on a three-fly nymph rig. Add enough split shot to get it deep, fast. Focus on inside bends, eddies, and pockets behind structure. These are places where fish can hold without burning energy.

Pro Tip:

Paul adds, “Use fluorocarbon tippet on this one—it helps cut through the current. I run 3X to the Pat’s, even in ‘technical’ water. You’re not fooling fish in gin-clear spring creeks here. You’re feeding bruisers in the trenches.”

2. Formally Known As Prince – Size 12–16

The Utility Player

A modern twist on the classic Prince Nymph, the Formally Known As Prince (FKAP) combines flash, movement, and just the right touch of sophistication to catch trout during runoff’s chaos.

Why it works: This fly mimics a range of aquatic insects, from caddis to emerging stones. Its flashback and hackle provide visibility and realism in dirty water.

Paul explains:

“It’s a crossover pattern—it reads as a lot of different food sources. Trout aren’t looking for perfection in May, they’re looking for calories. This fly is like a cheeseburger that kind of looks like a steak. They’re gonna eat it.”

How to fish it: Tie it as the middle fly in your rig, on 3X or 4X fluorocarbon tippet. Let it ride about 12–16 inches below the Pat’s. The FKAP brings attention without the bulk and will often be the first fly that hooks smaller, faster eaters.

Pro Tip:

Paul’s trick? “Try fishing this in riffle tailouts at midday. Even in high water, trout move up when the sun warms things a few degrees. The FKAP looks just buggy enough to crush.”

3. RS2 – Black, Size 18–22

The Closer

Don’t let the size fool you—this tiny emerger might be the most critical part of your May rig. When fish are keyed in on small mayfly emergers, especially mid-column or in soft seams, the RS2 finishes the job.

Why it works: The black RS2 stands out just enough in stained water, while its slim profile and flashy wing bud screams “emerging mayfly.” Even in runoff, trout will eat RS2s—especially in quieter back-eddies and tailouts.

Paul’s take?

“People always assume May is about big bugs. But trout still feed on the little stuff. The RS2 gives you a finesse option on the end of a heavyweight rig. Think of it as your relief pitcher—it seals the deal when the other flies get ignored.”

How to fish it: Tie it as your third fly (dropper) on 4X or 5X tippet. Keep it 12–14 inches behind the FKAP. It will ride higher in the column or trail behind in softer water—perfect for fish feeding just off the bottom.

Pro Tip:

“Look for foam lines and slower water next to the bank,” says Paul. “Those are RS2 zones. You might not see the take—it’ll just stop. Set on anything weird.”

Fishing the Rig: Putting It All Together

Here’s your May game plan, rigged up:

• Point Fly: Pat’s Rubber Legs, Size 8 (on 3X)

• Middle Fly: Formally Known As Prince, Size 14 (on 4X)

• Dropper Fly: RS2 Black, Size 20 (on 4X/5X)

• Weight: Add split shot 6–12” above the Pat’s

• Indicator: High-riding foam indicator

Focus on seams, eddies, and soft water near the bank. Fish aren’t out in the middle of the current—they’re pressed to the edges where they can eat without working too hard.

High Water Doesn’t Mean Low Opportunity

Many anglers pack it in when rivers rise. Don’t be one of them. The truth is, trout still feed actively during runoff—they just do it differently.

“Fish still see incredibly well in dirty water,” Paul emphasizes. “Remember, they’re used to this. Their lateral lines are dialed in, and they pick up contrast and vibration more than we realize. Get the right flies to the right place, and they’ll eat.”

Use that knowledge to your advantage. Choose flies that push water, stand out in color or silhouette, and offer a buffet of options in one drift.

Where to Get These Flies

You can pick up all three of these essential patterns—plus a killer selection of other spring favorites—at Golden Fly Shop in Golden, CO and Castle Rock, CO. The crew there knows their stuff, and they’ll get you dialed in for your local flows.

Bonus: Ask about Paul Killino’s favorite local patterns or a guided trip with Colorado River Outfitters. Spring fishing with an expert makes a world of difference, especially when flows are high and the fish are moving.

Final Thought from Paul:

“Don’t be afraid of big water. Learn it, respect it, and fish it smart. Spring’s got some of the best fish of the year—if you show up with the right plan.”

So go armed, go smart, and go get ’em.

Tight lines this May. And remember—your starting lineup matters.

To book a trip with Paul Killino or any of our seasoned, professional guides, give us a call at 970-236-1937.

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@colorado.river.outfitters