When I first acquired the deserted farm on the banks of the upper Mississippi in the Minnesota north woods more than 20 years ago, beavers were sparse. Here and there some of the many lodges were occupied. Nearby farmboys and a handful of trappers -- and modest fur prices -- kept the population in some sort of balance.

I heard stories of the beavers' mischief, flooding roads and inundating farmlands, of neighbors dynamiting dams and trapping them. This sounded needlessly vicious to me, an extreme extension of the ethos of man shaping the world to his convenience at the cost of ecological balance and, ultimately, environmental sanity. My neighbors did not argue, and merely arched their eyebrows, implying that I would learn in time.

The number of beavers declined, until the sighting of an occasional stray in search of terrain and companionship became a rarity. Lakes and creeks are abundant, and the growth of aspen and other foods sought by beavers is rampant, so that it seemed a shame not to have more of them around. This thought came to me often during drought years when water levels dropped and the fire hazard was severe. Then the retained water backed up behind the beaver dams would have been very welcome; but there were no occupied lodges nearby.

They returned inexplicably in modest numbers, and hard on their heels came the trappers. I posted my land, tried to locate the trappers who came up the river and overland, whose traps and tracks I found but whose ghostlike comings and goings eluded me. I sprang the traps, which they reset. I removed the traps and they sank the swimming raft floating on barrels on my lake with gunfire one day when I was away at work. Then the beavers were gone again, the last lodge trapped out and the conflict became passe.

Game wardens and foresters at the State Department of Natural Resources listened sympathetically to my pleading for the transplanting of beavers into my denuded lake.

"If you have nuisance beavers somewhere and have to trap them, you can put them in my lake," I suggested.

"Live trapping is very time consuming; we don't do that any more," they explained. Where absolutely necessary, licenses were issued to local residents to trap the beavers, killing them and taking their furs. Ordinarily, though, it was a matter of gritting their teeth, planning and building roads and bridges with the possibility of beaver dams in mind and sometimes installing sluices that they opened in the mornings and closed at night, thus baffling the nocturnal beavers as they sought the "leak." No other effective baffles or control have yet been found.

"You're sure you want beavers?" they asked.

"Certainly." I tend to be emphatic and certain, to my eventual regret.

They returned in numbers and suddenly after a few years. We watched with delight as the old lodge on our lake was renovated and expanded, and two lodges were refurbished on the next lake. It seemed to me that their appetites were modest and their incursions for building materials well within the provender of my woods, without undue damage.

However, they dammed the outlet of the lake, and the water rose ever higher, far beyond their needs. I opened the dam to lower the water level, and they rebuilt it bigger and better by next morning. Woven into the dam structure, amid branches and clumps of mud, was lake bottom debris: cow and pig bones (I had heard tales of farm animals getting mired, then being lost in the silt of the lakeshore long ago), broken glass and pieces of some particularly garish blue and white dinnerware. I did not know the source of these shards, which my wife refers to as Blue Willow. ("Let them haul up the pieces, maybe we can glue them together and wind up with a complete set," she says, but I fail to see the humor; somehow blue and white pieces of plate clash with my image of north woods wilderness.)

After a second and third day of opening the dam, only to find it bigger and better each time than it had been before, I arrived one morning to find it not only rebuilt, but across the top of it a sheet of plastic neatly anchored with branches and mud. I had lost the sheet months before in a windstorm. So much for beavers in the wilds; ours were scavengers pure and simple, too lazy to cut their own dam materials and unearthing human debris and middens as an unsightly labor-saving device. I gave up for the season.

We posted the land and kept a close lookout for trappers in winter, and this time there were no ugly confrontations for there were so many beaver all about that my peculiarity in protecting them did not interfere with the trapping; there were other places for the trappers to go.

It was a long winter, with an unusual amount of snow; with the arrival of warm weather and the spring runoff, the beavers reemerged, their numbers augmented by progeny who had to be taught dam building.

I am told by some neighbors that beavers react to the sound of funning water, taking this as a breach of their dikes.If true, this spring's record runoff drove the beavers to heroic efforts of dam building. A tote road, kept open for fire control access, was flooded. The lake expanded in size. The children's swimming hole up the creek became deep enough for my use. The greening trees around the periphery of the lake turned brown as the waterlogged roots rotted and died. The emerald lake was no longer ringed in green, but by brown and sere skeletons of birch, cedar, pine and aspen. Then the access to the building site for our new home became waterlogged and, finally, impassable.

The return of the beavers has produced an unsightly array of dead and dying trees, inconvenience and impediment to our use of the land. In the larger framework of a wilderness ecosystem, with its long-range cycles and episodes, the beavers' presence and alteration of the environment are productive and necessary. On the smaller scale of our land, coexistence -- so ardently sought by me for so long -- has now become seemingly impossible.

Live-trapping is difficult and time-consuming.

Operating a sluice installed in their dam -- opening it in the morning and closing it in the evening -- becomes a major chore, and represents an installation expense.

Dynamiting the dam, which frequently drives out the beavers, or trapping (killing) them go against my grain.

I amuse friends by describing the recipes I intend to use for Christmas dinner of roast beaver, and my plans to make a beaver coat for my wife ("But I want a storebought coat." she expostulates).

Meanwhile, our house-building project is stalled, no alternative sites being feasible, and more trees around the lake are dying. I grit my teeth while they whet theirs. I contemplate beavercide while my children, groomed and conditioned to a love of wildlife over the years, tell me that the young beavers are "cute" and of watching them at close range.

Tonight an engineer is to visit to advise me on the cost of building a bridge.