ON THE ST. CROIX RIVER — Fishing with Bob Nasby is like fishing with a human fly shop. Always while on the water he totes with him medleys of homemade feathers and hooks, each arranged sequentially and collected in neat compact cases, protected as if they were numbers in the nuclear code.

Dennis Anderson

“Let’s try this popper,” Bob said, extracting from its container a thumb-sized chunk of plastic, one end of which trailed a plume of deer hair.

This was on a recent Thursday morning, warm and clear, and we were peppering this river’s shorelines with flies we thought might fool smallmouth bass, or trick a northern pike or a muskie.

Enjoying the rhythm and cadence of looping a long line into the bright morning, I threw a popper, while Bob cast a streamer-looking affair.

“I call it the ‘Banjo Minnow,’” Bob said of his fly. “But not that Banjo Minnow.”

The second reference was to a bait sold years ago and perhaps still today by TV infomercial. Victims of this alleged world-beater lure were said to be big fish caught willy-nilly, and in a fever my then two young sons and I couldn’t wait to dial the provided 800 number to lock in an order for five or six dozen, fretting even then that our requisition was too small.

“I still have plenty of those Banjo Minnows,” I said, “should you need them.”

During the 48 hours before our arrival, the St. Croix had shed what seemed like a couple of feet of topline, reducing itself almost overnight from a really flooded river to a marginally flooded river.

For no particular reason we took this as a good sign as we puttered into the river’s main channel amid the morning’s low angle of light.

So beautiful was the river and the steep bluffs bracketing it that en route we should have been gunnel to gunnel with other deadbeats like ourselves. Instead we had the river virtually to ourselves, save for an eagle that circled high over the Wisconsin bluffs, aloft on the morning’s warming currents. Save also for the odd mallards that waddled along the shoreline, and for the occasional boat that ran upriver or down.

Dennis Anderson photo
A smallmouth bass caught on a popper cast by a fly rod on the St. Croix River.

Generally, we fished in the Stillwater area.

This stretch of water, the portion lying between Taylors Falls and Prescott, Wis., the Lower St. Croix, is home throughout to smallmouth bass and, in fewer numbers, to their bucketmouth cousins, as well as countless other fish.

Johnboats can be used here. But generally application of these craft for angling is more appropriate above Taylors Falls, where the river narrows as it trails toward its headwaters in northwest Wisconsin.

Bob and I were perhaps 20 casts into the outing when a fat smallie rose from the depths and smacked my popper. This occurred about mid-retrieve, or farther from shore than we thought it might, for which we didn’t have a good explanation.

The fish broke the surface once, then again, pulsing my rod tip into the river, then out, before seeking refuge beneath our boat.

Except for the ripples that expanded concentrically from the fish’s disturbance, the St. Croix was nearly mirror-flat.

“Will you look at the shoulders on that guy!”

This was Bob feigning the role of an out-of-breath TV fisherman, for whom, typically, no reaction is too exaggerated when a fish has been hooked.

“Right,” I said, dislodging the popper at boatside before sending the fish swimming.

A fly casting instructor and member of the National Freshwater Fishing Hall of Fame, Bob introduced his grandson, Bobby McGraw, to fly casting at age 5. Now a champion competitive caster, Bobby, 31, throws a fly with laser-like accuracy, his line unfolding in loops tight enough to sail beneath tree limbs hanging low over riverbanks.

Next to hit my popper was a dandy northern pike, weighing perhaps 5 or 6 pounds. Like the smallie, the northern struck the popper about midway between shore and our boat.

Then came two largemouth bass and two more smallmouth bass.

Bob had spooled a spey line onto the 7-weight rod I was casting, and even in my tenuous hand the line rocketed through the rod guides, carrying the popper to its intended target.

As we fished, I recalled a time years ago when Bob and I were in the Marquesas Islands off Key West, tossing flies at tarpon.

On the day’s last drift, Bob made a pinpoint cast with a 12-weight rod, turning a bruiser of a fish toward his fly. We were poling through water 4 feet deep when the tarpon took the bait, and when Bob buried the fly in the fish’s bony mouth the tarpon went airborne repeatedly.

That Thursday morning, we were on the St. Croix, not off the Marquesas. And these weren’t tarpon we were fishing.

But overall the two outings weren’t dissimilar. The idea in both, as in all fishing, was to roll the dice, to see what happens.

And in our case, to cast a fly.