The days of world record brown trout seem to be behind Flaming Gorge Reservoir. But the 92-mile-long Wyoming and Utah reservoir last year began to produce 50-pound lake trout, or Mackinaw, and the lake record is 51-1/2 pounds.

Those 50-pounders are 30 years old, about as old as the reservoir itself, says Lamont Jensen, a Sunset, Utah, biology teacher and Flaming Gorge angler.Needless to say, not many of those big old fish are swimming around, but the chance of hooking up with a lake trout only 15 pounds short of the world record should be enough to entice plenty of anglers to Flaming Gorge.

Well, not exactly. The reservoir draws fair crowds in spring, when most people fish for Mackinaw, and in summer, when smallmouth bass anglers, trout anglers and water skiers join the pack.

But the area's big year-round draw is the Green River below the dam, where fly fishing pilgrims arrive from all over the U.S. The world-class trout stream diverts attention from the reservoir.

In winter, when the Mackinaw swim in shallow waters, precious few anglers follow them, and fewer fish the narrow canyon waters at the southern end of the lake, from Manila to Dutch John.

Jensen likes to fish these productive canyonlands, casting 3/8- and 1/2-ounce white maribou jigs where he and his boat are dwarfed by tall cliffs and mountains that give the lake's lower meanders the appearance of a fjord.

Boating anglers interested in going to Flaming Gorge should go prepared, especially in winter, for cold weather and hazardous winds from the high desert that can whip up dangerous waves without warning.

Because few boats ply the reservoir in winter, fishermen need to be sure their equipment is working properly, and they would be wise to buddy up with fishermen in a second boat.

Gregg Meyer once found himself up the canyon with misfiring spark plugs, lost and motoring among Flaming Gorge's steep-banked canyons as the surface turned to ice.

"We couldn't climb out of there. Anyway, each canyon looked like the next, and we wouldn't have known where to walk," he said.

Eventually they found their way out of the maze. Now he has a spare set of plugs.

According to Jensen, Mackinaw fishing can be very good., The big char stay in relatively shallow water until April.

He feels, though, that Flaming Gorge has seen better days. He blames an apparent reduction in Mackinaw numbers on the increasing skill and improved equipment of summer trollers, who use downriggers and steel line to haul the fish up from their deep summer haunts.

"You get 150 boats working one school of fish and, sooner or later, they're going to do their damage," he says.

Utah regulations allow anglers to keep eight trout and salmon in aggregate per day, no more than two of which may be lake trout.

But a new slot limit for Flaming Gorge effective Jan. 1 will protect large mackinaw under 35 inches. Non-residents can buy a five-day Utah fishing license for $15 and pay $5 more for a stamp that will permit them also to fish in the Wyoming end of the lake.