Delta Largemouths: A Topwater Fly-Fishing Paradise

This article originally appeared in the May 2007 issue of Fly Fisherman magazine.

Editor's note: Kevin Doran passed away in 2022. 

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Looking through the camera lens, I'm thinking to myself, "Man he's got this game down." With a smooth underhand casting stroke, Kevin Doran (KD) does his thing. The fly lands with such precision that it almost demands to be eaten. The deer­hair bug penetrates the dense tule cover and lands near a small patch of duckweed. Kevin lets the fly settle, and we both watch as a nice bass of about 4 pounds smashes it.

Most Delta fly anglers fish in the fall and winter for stripers, and most giant largemouth caught on the fly are accidental catches. A local fly fisher caught a 17.75-pound largemouth a few years ago. Imagine if more fly anglers actually targeted largemouth as aggressively with large­ mouth tackle and tactics as they do fly fishing for stripers. The number of giant fish caught would be impressive. I ask Kevin why he spends half his fishing year on the Delta chasing largemouth bass.

"Big bass and lots of them," he says.” I catch them all season long fishing floating lines and topwater patterns. In my eyes it is the most consistently enjoyable fly fishing I do on the Delta ... or anywhere for that matter. I look forward to it every year as the striper season winds down in late March. It keeps my casting sharp, my anticipation high, and to quote one of my clients: 'It's like a video game.’ There’s always a new piece of cover to cast to. It presents every enjoyable aspect of fly fishing."

Delta Access

You can get the delta from many major roadways. To the west is the city of Antioch, to the south Tracy and Manteca, on the east Stockton, and Sacramento on the north. Major thoroughfares include highways 4, 580, and 5. Driving time from the San Francisco Bay area is less than two hours to most of the important access points.

The Delta is the West Coast version of the Louisiana bayous or the Florida Everglades. More than 750 species of plants and animals call it home. The habitat is fertile, vibrant, expansive, intricate, and loaded with bass.

The two most significant river systems feeding the Delta are the Sacramento (flowing in from the north) and the San Joaquin (entering from the south). Other feeders include the American, Mokelumne, Cosumnes, and Calaveras rivers. These waters directly affect the quality and quantity of fish populations and habitat through the year.

The Delta today is a combination of man-made structure and sheer natural beauty. The fact that settlers created a series of levees almost 200 years ago to harness these rivers is a critical part of the fishery. Back in the mid-1800s,the first levees were constructed from peat soil. In a matter of decades, around 1870,the preferred method of construction became clamshell dredging, and by the 1930s, farmers had cultivated more than 550,000 acres on 55 man-made islands. Anglers now travel and explore the levees of bygone days.

Tidal Impact

The Sacramento/San Joaquin Delta system is one of the largest estuaries in the West, a maze of nearly 1,000 miles of navigable waterways loaded with cover and structure and greatly influenced by tidal movement. Tides are critical: They improve or impair habitat access, forage base, water temperature, floating cover, salinity, and more. Therefore, tide charts are a key element of your largemouth fishing.

Since the Delta is so vast, the tidal movement throughout the entire system occurs at varying times. If you’re using a generic chart for northern California, the peak times displayed require adjustments of up to an hour, depending on where you are. Precise tide correction tables are located in the back of most tide booklets, and Delta-specific charts are sold in various tackle shops and marinas around the Delta. I use a product called Tidelog (tidelog.com, 415-868-2909) to predict Delta tides.

Doran pays particular attention to moon phases when seeking the best tide cycle. Neap tides create prime conditions for targeting Delta largemouth, especially for topwater fishing. The neap tides occur on the opposite weeks from the new- and full-moon phases. In other words, you should try to hit the water during a quarter-moon phase whenever possible. Neap tides create a relatively stable habitat for long periods, with a favorable exchange of water between low and high tides.

Also worth noting is the intensity of the movement within any tide cycle. My highest success rates are tied directly to “the magic 90,” which is the window of opportunity that begins about 90 minutes after the change of the tide. The best action takes place around mid-tide, so make sure you are in position to maximize the moving water that occurs from 1 1/2 to 3 hours after dead low tide. Mid-tide has maximum current velocity.

Hitting the Mats

Spirogyra is an algae that flourishes in high heat and calm-water conditions. The algae forms mats that often look and feel like cottage cheese, and the colors are wild with yellow, rust, and various shades of green. These mats are among the best places for Delta largemouth. The KDM Rat was specifically designed for this fishing.

Spirogyra usually blooms around late May, first appearing as a thin layer of surface scum. As the water warms in the summer, the mats expand in surface size. They also become thicker, which provides shade and creates superb bass habitat. The mats also provide bass a feeding opportunity because they are home to dense populations of frogs, mice, and other food items. Around early October the mats rapidly deteriorate as the weather cools.

As the tide peaks, follow the fish as they reposition themselves to take advantage of newly flooded areas. The opposite is true on a dropping tide. To estimate prime bass feeding periods, establish the time of the peak high tide, add 90 minutes into the dropping tide, and brace yourself for a second session of great angling.

Another advantage to working the neap tide cycle is that the water is usually clear. With less agitation, there is less suspended debris in the water.

Spring tides occur during the new- and full-moon phases of the month and have nothing to do with the spring season. Spring tides always develop the strongest currents and greatest exchange of water between the low and high points of the tide. These stronger tides wash more sediment off weeds, riprap, and the surfaces of mud flats, and frequently create cloudy water conditions.

Cover Density

Tides also impact the density of weeds, grass beds, and the nonnative waterweed Egeria densa. Here’s a simple rule to live by: the lower the tide, the denser the vegetation. As the tide rises it also lifts and expands the matted blades of grass or stems of Egeria and other vegetation. This creates open space for bass to roam and feed.

Floating islands of hyacinth also vary in density. Strong tides and winds drive the plants into amoebalike colonies, and incoming tides drive the hyacinth beds toward shore, building massive concentrations of the plant against other structure. Since these relationships are built on a fluid medium, rapid changes can occur throughout the Delta system depending on the tides. Are you staring down the lane of a hyacinth-clogged slough? Just wait a few hours and you could be facing an entirely new habitat of open water with small floating islands of green cover.

The Surge Zone

Channels between the riprap, tules, or deadfalls and the bank provide action all season. We call these channels surge zones because they fluctuate in size depending on the tide, since an incoming tide creates a deeper channel. The opposite is true of a falling tide. Our natural inclination is to look for wide areas, but depth is the key. Bass live in a vertical world. Instead of a 5-foot-wide channel or surge zone that is only 11/2 feet deep, bass prefer a 2- or 3-foot-wide area that is 3 to 6 feet deep. Think “column” rather than “raceway.” It’s a compact zone that becomes a perfect ambush point for prowling bass.

By the Month

Topwater action is best from March through October. Expect to find the bass engaged in prespawn activities in March when water temperatures are in the high 50s. Winds often push out of the north and, when combined with runoff waters, produce turbid, difficult fishing conditions. Rivers also impact the early season by keeping the Delta water cold. In these conditions, you should move off the main channels to fish warmer waters with slower current, such as lakes or backwater sloughs.

April provides a fishing window just before full spawn. You should focus on the flats adjacent to deeper waters and between islands. Flats with depths of 2 to 6 feet are ideal habitat. As water temperatures climb into the low to mid-60s, cool foggy mornings may keep the bite down and afternoons usually provide the best opportunities for topwater action. Damsels and dragonflies take flight late in the month and as conditions stabilize, turtles are more active, pheasants cackle, and largemouth bass attack surface flies aggressively.

The late- and postspawn cycles occur in May and June. Focus on transition zones such as drop-offs, fast to slow currents, riprap to vegetation cover, and open water to dense cover. Water temperatures are usually in the mid to high 60s during May and reach the 70s in June. Damsels and dragons are abundant; calm conditions prevail; and weedbeds and algae mats thicken, providing excellent cover and forage habitat for bass. Bass fry appear in early May and panfish fry in June, so small sliders and waking-style flies match these baitfish.

It gets hot in July and August and water temperatures are often in the high 70s. Focus on the morning bite. Bluegill and crappie feeding on top indicate that bass will also chase surface flies. Frogs, mice, and dragonflies are all on the menu. Spirogyra mats become the dominant surface cover, so larger weedless deer-hair flies are the best patterns. Your flies should leave skid marks across the top of the algae, and you should concentrate your presentations tight to other cover.

Cast into pockets behind woody debris, work your fly through tule reeds, fish cuts between peat berms, and work the small-channel current seams. As the sun sets, rework the riprap walls where bass favor rocky cover that holds heat into the evening.

Early fall water temperatures dip back into the low 70s, and surface mats begin to thin and die in the waning daylight. September and October have the clearest water of the year. It’s finesse time. Mornings are cold, and there is a drop in the abundance of large food items. You should downsize your fly patterns accordingly.

Equipment Choices

Topwater fishing calls for 7- to 9-weight outfits to handle wind, heavy cover, and current; and I prefer rod designs that provide a fighting butt for leveraging bass out of thick cover.

I also prefer weight-forward, bass-taper, floating lines with short (34- to 36-foot) heads and sharp front and rear tapers. Overlining your rods by one or two weights helps to deliver bulky flies in tight casting conditions. Use a short, sharp casting stroke for quick deliveries when casting a short line. Weedless is the key to fly selection. You must be fearless with your presentations, casting into, over, around, and through cover.

Dahlberg Divers, Whitlock Swimming Frogs, and KDM Rats are all effective deer-hair designs. Foam Gurglers are another good choice when low-profile surface sliders are the ticket—include sizes 2 through 4/0. To complete your topwater fly selection, add a few dragon- fly imitations in blue/black, orange/rust, and green.

KDM Rat Fly Recipe

• HOOK: #2/0-4/0 Mustad 34011 or equivalent.
• THREAD: Flymaster Plus.
• BODY: Deer hair, unclipped.
• LEGS: Long, curved hair from base of bucktail.
• LEG CEMENT: Amazing GOOP.
• BELLY: Light-activated resin such as UV Knot Sense or Tuffleye.
• EYES: Doll eyes, plastic, 3/16" to 1/4", yellow or gold.

NOTE: The rear third of the hook shank is bent upward slightly and the fly is built on the opposite side of the hook shank. The long, unclipped deer hair from the body shields the hook point making it weedless.

Final Thoughts

Kevin Doran grew up exploring the Delta backcountry. He was the only Delta guide I knew who specialized in largemouth bass with fly tackle and techniques. For a complete list of other Delta guides, see danblanton.com. Kevin and I are bass addicts, and each fishing day we share our inquiries and observations—what we see, hear, learn, and how we adapt our fishing techniques. This teamwork is a winning formula for solving the challenges of the Delta’s largemouth fishery. This is the Delta I know. This is the Delta that is in my blood. This is a perfect largemouth bass fishery for topwater fly rodding.

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Ken Hanley is the author of several books, including most recently Fly Fishing the Pacific Inshore: Strategies for Estuaries, Bays, and Beaches (The Lyons Press, 2003). He lives in Fremont, California.

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