One of the ironies of the fall fishing season is that the best angling for the mid-atlantic's premier saltwater gamefish-the striped bass-will occur in freshwater .

This wasn't always the case. Responding to fall's dropping temperatures, stripers once broke water in acre-wide schools, giving exceptional sport throughout the Chesapeake Bay. Though anglers have stumbled on a few promising schools of surfacing pansized rock in recent weeks, such action is tough to come by in the brine these days. For quality fall rockfishing, lake prospects are as bright as saltwater prospects are dim.

Forty years ago there was no such thing as freshwater striper fishing. But when workers closed the gates on sprawling Santee-Cooper Reservoir in the lowlands of South Carolina in the early '40s, they did more than control malaria-carrying mosquitos and create hydroelectric power. They also midwifed the first self-sustaining population of landlocked striped bass.

It took a decade or so for anglers and biologists to fully fathom this, but once they did, freshwater striper fisheries snowballed.

Virginia has been a leader in developing striped-bass culture. Its Brookneal Hatchery has bred over 50 million striped bass and most of them have gone into Virginia's lakes. From now to December, four of them will offer top prospects for rockfishing: Anna, Gaston, Kerr and Smith Mountain. Anna is a two-hour drive away, Kerr and Gaston four hours. Smith Mountain, five.

Anna's stripers have yet to draw a great deal of angling attention and the fish haven't been pinned down to any truly consistent patterns. Guide Bill Mathias (703/894-5725) and others who fish the lake have had best results using depth-finders to locate fish near the dam, then juggling bucktails or Hopkins spoons over them.

Some stripers also reportedly hang out near the Route 208 bridge. Drifting with live minnows at depths of 15 to 30 feet near the pilings should be an effective tactic.

Gaston is perhaps Virginia's most overlooked striper spot. A straight shot down I-95 to the N.C. border, the lake lies on the downstream side of Kerr Reservoir. As such, it's buffered from the silt and debris that tumble down the Roanoke after heavy rain. It vies with Back Bay for top largemouth lake of the state, but its stripers go begging.

And there are some whoppers waiting to be caught. I pulled a 20- pounder out of here on a wispy ultra-light rod and 6-pound line a few years back. Mickey Johnson, who lives on the lake, regularly hauls in a couple of rock a year in the 23-to-25 pound class.

Johnson's tactics are simple, but devastating on the big bass in fall. He uses a spincast outfit, 14-to-17 pound line, a couple of split shot, and a 2/0 hook. On the hook he impales a frisky four-inch shiner.

Johnson favors bridge abutments where there is a current flowing from water being released at the dam, and also the area near the dam itself. He just tosses the bait out and waits for a fish to come along and virtually rip the rod out of his hand. (He's lost a couple of outfits to rampaging rock.)

Those who prefer a more active approach can use this same rig, but cast out and retrieve the minnow slowly along the bottom. The first few hours after dawn, and from dark on into the night, are best times.

Breaking fish in the open water near the dam offer another possibility on Gaston. For this anglers use Little Georges, bucktails, and spoons. A fast boat gets you to the surface-churning fish before they sound.

Kerr Reservoir, immediately upstream (west) from Gaston, is one of a handful of lakes in the country with a naturally-reproducing striper population. Don Diamond of Clarksville Marina says striper fishing is just getting underway and should continue to improve through November.

Breaking fish offer fast sport on Kerr when you can find them, but the most consistent action comes to troller. Mornings and evenings are top times, and the favorite lure is a 3/4-to 1-ounce bucktail (white or yellow) with pork rind or plastic worm trailer. Mack Elliot (804/374-2338) of Clarksville guides for stripers on Kerr.

Smith Mountain is king of Virginia's striper lakes, considered one of the top two or three rockfish spots in the country. The lake gets half-a-million striper fingerlings a year, some growing to outlandish sizes.

Guide Dale Wilson (703/297-5650), who fishes the lake practically every day, says it's not unusual now to find schools of several thousand rockfish busting the surface as they feed on shad over two-or-three-acre patches of water. The S-curve and the deep water near the dam are good spots.

The first and last two hours of daylight are best. "If you get cloud cover at this time of year," says Wilson, "sometimes the fish will break off and on all day long."

White bucktails and Striper Swiper surface plugs are Wilson's favorite lures for Smith Mountain's autumn stripers. Ask marina operators where the current hotspots are for breaking fish. You can often tell where action is expected by the presence of boats waiting motionless in mid-lake, like herons poised on a stalk for baitfish.

Position your craft a polite distance away and wait along with them. If conditions are right, you may shortly witness one of the most stunning sights in freshwater fishing as immense schools of 10-and 20-pound rock boil the surface of the lake to a turmoil.

Come to think of it, was the Chesapeake's fall striper fishing ever this good?