The big beaver couldn't have been less impressed. It slumped dolefully down the bank from its daytime resting place, casting a go-back-where-you-came-from glance our way as we eased along the shoreline of Occoquan Reservoir.

"See that," said optimistic Jim Donald from his perch in the stern. "Now you know there's got to be fish here, or that beaver wouldn't be so fat."

Almost as he said it, his line went taut. With one hand, he dropped the anchor over the stern and with the other he pulled back on his fishing rod to set the hook. He reeled in as the boat lurched to a stop. "Oh boy," he said, "this one's got some size to it."

We never did find out how much size because that fish quickly became one of the ones that got away during our all-day expedition on the 1,600-acre impoundment near Lorton.

If it was as big as it felt it would have been the highlight of the day. We were a far cry from skunked as we cruised the deep coves and channel beds, but we never did put a big fish in the boat.

Not that it mattered much. Donald's self-ordained mission was to prove you could find wild country within a half-hour drive of the big city. The beaver took care of that. If we neede more, there was the mama hawk out hunting while her young squawked from their nest in a high pine, a pair of Canada geese off Sandy Run, ducks along the shore and countless swallows flittig across the water.

But not much in the way of fish. We had plenty of incentive. Park manager Rock Allen had weighed in a state record 4-pound 7-ounce white bass at the Fountainhead park headquarters two weeks earlier, and an 11-pound-plus northern pike had been taken the previous week.

But all we seemed to be able to entice were small bass, largemouths in the one- to two-pound class.

Occoquan's massive size - it's the biggest by far of the close-in impoundments - did not seem to carry over to the fish it supports.

The big fish wouldn't cooperate so we made it hard for ourselves. I managed to make one of the most improbable catches of the still-young season when I looped a cast over the bare branches of a young sycamore in a cove.

I was scratching my head, trying to figure out how to get the lure back out of the water and over the branch. Suddenly the surface boiled as something came up to the top and snatched by Rebel plug.

An 11-inch largemouth managed to hook itself and then wear itself out battling the pull of the tree. Pretty soon it gave up and we motored over, snatched the line and lifted the sad little fish into the boat. Donald took a picture of the bass and the three that caught it and then we set both free.

Donald's idea was that he would spend the morning showing me how to catch Occoquan bass and I'd spend the afternoon teaching him to catch crappie. The first part worked fine as we pulled in a half-dozen bass.

But after lunch the tables turned. Even with the scrappy minnows and night crawlers Allen had sold us at 6 a.m., we couldn't find the speckled panfish.

Finally, we gave up and went back to plugging for bass, agreeing that the crappie simply weren't there.

Which was fine until two guys from Quantico showed up at the ramp as we were pulling the boat out with 70 (count 'em) crappie they'd picked up in 2 1/2 hours.

"They were in five feet of water, back in every cove we tried," they said. "We got 'em on little jigs."

Oh well, the aim was to see Occoquan, not necessarily conquer it.

The reservoir was formed when 120-foot-high Occoquan dam was built in 1958. The Northern Virginia Parks Authority entered the picture in the '60s and has helped keep progress from ruining the idyllic lake that supplies drinking water to 600,000 people.

There are still signs along the Fairfax County shoreline advertising lots in Port Charlotte, a planned community that thankfully will never happen. NVRPA bought it out. In the last 18 years, the agency has accquired 4,000 acres around the lake; that's about all the land there is on the Fairfax side. It means no development will occur, a blessing for everybody.

But Occoquan divides Fairfax from Prince William County and Prince William owes no allegiance to NVRPA. The result is that houses are popping up like mushrooms on the southern shore of the lake.

It's not enough yet to ruin the serenity of Occoquan, but NVRPA public information office Dorothy Werner conceded, "We're worried" about rampant development, pollution and overpopulation.

Two NVRPA facilities serve Occoquan fisherman - Fountainhead and Bull Run marina. Both offer handsome rental skiffs for $3.50 a day with which to attack the 100 miles of shoreline. Outboards up to 10-horsepower are permitted. The scene can get crowded on weekends, but on Tuesday we counted just three other boats. That leaves a lot of room.

Occoquan was knocked for a loop by the drought last year. Water levels were down so badly that the boat ramp at Fountainhead was high and dry, 100 yards from the water's edge.

But the drought is over, levels are back to normal and the fishing does not seem to have suffered.

To get to Fountainhead, which is in the heart of the reservoir, take I-95 to the Lorton exit, state Rte. 642 west to Lorton, then Rte. 123 north a couple of miles until you see the signs. The park opens at 6 a.m.