"Where are the guns?" Lot Cooke quizzed with feigned misgiving as we loaded the 17-foot Grumman with rods, tackle, life vests, paddles, cameras and lunches.

No explanation was needed.

The recent influx of frosty, dry air from Canada breathed new life into both fish and fishermen. It was so cold in the mountains of northwestern Virginia, in fact, that Cooke thought surely he must have slept through two hot, steamy months and now was embarking on a float hunt for ducks and squirrels.

The morning indeed seemed more like October than August as we pushed off into the foam-flecked waters of the Shenandoah River's North Fork.

The mercury read 52 degrees. For several nights previous it had plunged into the mid-40's, forcing Shenandoah Valley residents to stoke the winter fires earlier than most can ever remember.

Wildlife along the river was unusually active, as if its time clock had been wound forward too. Birds and beats seemed eager to feed and hastily make their preparations for the encroaching winter.

The river was alive, all things energized by the high barometer and cold, dry air.

But even though game wasn't on the agenda, we easily convinced our selves this was a fall outing. The bronzebacks were striking topwater baits with fervor and fighting with the total abandon they normally reserve for autumn, when the river turns cool and the fish know they must feed heavily to gain fat for the lean winter months.

For all intents and purposes, it was (and is) fall on the Shenandoah. No longer are the brown bass hanging deep where only bottom-bounced baits will raise them out of their summer stupor. They are striking high, leaping even higher with a show of acrobatics that should have all dedicated light-tackle fishermen reaching for their gear and rushing to the river.

Lot and I stroked a mere 50 yards downstream from the put-in point before we could resist the urge no longer and pulled out our tackle. A spinner was on one rod, in case the bass were still deep and needed sub surface prodding. A Rapala, the classic balsa lure handcrafted in Finland, was knotted to the four-pound mono on the other outfit.

Our hope was strong that the bass would be ready for the near-surface action of the minnow plug. It took only minutes confirm that this was indeed the case. The spinner drew one short take, the Rapala four strikes and three fish were caught on the first six casts.

Better still, the smallmouths went for the balsa lure as soon as it touched down and was resting on the surface. They busted into it with the force of fish twice their half-pound size. Soon we both had on the delicate wood lures and were busily probing the shaded water near the banks and deep pockets at the tails of pools. The canoe drifted haphazardly, first careening up, then floating downstream with the countering forces of wind and current.

The bass responded with gusto to the thin silver plugs. Lot cast to a deep pocket near a boulder and twitched the lure with a jerk of the rod tip. It bobbed back up like a wounded baitfish and three energy-charged smallmouths streamed towards it.

True, the fish also struck on a slow, steady retrieve which brought the plug six inches below the surface. And yes, it was a surer method of booking the bass than bobbing the lure back on the surface.

But neither of us could resist the temptation this top-water technique posed. Watching the feisty bass rush at the lure and splash a quart of water in every direction as they slammed into it was a thrill in itself, whether the fish were hooked or not. And many were stuck with the barbs -- up to 25 in one pool. When they were impaled, the smallmouths leaped twice as frequently as they had two weeks earlier, before the cold snap. Three and four jumps per fish were common.

We may see more days in the upper 80s, perhaps even the low 90s in Washington. But in the Shenandoah Valley not much of this fiendish weather is likely from now on. Cool air currents dominate the weather 80 miles west of D.C. at this time of year. Often the mercury will read 10 to 15 degrees lower along the Shenandoah during late August and September than it does in town.Nights are always frostier.

Fishing with top-water plugs, floating-diving minnows worked on the surface and deer-hair and cork fly rod lures should be excellent for the next two months. Lures such as the Lucky 13 and Tiny Torpedo will draw strikes when tossed within inches of the bank and worked back gently, particularly if the water is a bit high and murky (which it is not, as of this writing.)

Rapalas of 2 3/4 and 3 1/2 inches are the most consistent producers for this late season smallmouth fishing, however. Plastic versions don't seem to work quite as well, since they lack the buoyancy of balsa and land noisily, frightening the skittish bass.

You can work these in slowly and smoothly and catch fish, but twitching them on the surface is much more exciting. Strike back with a sideways motion when a fish swirls at the plug, to avoid jerking it back into your face or your partner's if the bass misses.

Weed growth is present in some sections of the Shenandoah now, and the better fishing occurs where such vegetation is lacking. Most of the bass are either close to the shoreline or in the tails of the deeper pools. With the cooling waters, bass no longer need to hang around the oxygen-rich riffles. We found few smallmouths in such locations.

To obtain a free map showing access areas on the Shenandoah, write the Virginia Game Commission, Box 11104, Richmond, VA 23230 and ask for a copy of their "Boating Access to Virginia Waters."