There are plenty of examples of waterways getting worse these days. It's essentially par for the course as development, agriculture and industry dump toxic loads into rivers and bays. How often do you hear of one getting better, by a long shot, almost overnight?

That's the story of the North Branch of the Potomac River, which a quarter-century ago was all but dead. The rocks were rust-orange and the water gin clear from coal mine seepage. Practically nothing lived in it.

The upper North Branch "was dead as a doornail from acid mine drainage," says Ken Pavol, who spent 31 years with the Maryland Department of Natural Resources before retiring as western region manager. "It's like that river was a corpse lying on a slab, and then it got up and walked."

These days Pavol makes a good chunk of his living as one of five trout fishing outfitters guiding anglers on the North Branch. That's how complete the revival is. It now supports a breeding population of sport fishing's most sensitive species. Stocked rainbow, brown and cutthroat trout and the odd brookie prosper here.

Pavol attributes the shift to three events: The placement of lime dosers along the stream to offset the acid drainage, completion of Jennings Randolph Dam in 1982, which gave the river a steadier flow, and upgrades to the effluent from the big Mead-Westvaco paper plant in Luke.

Pavol says the 27-mile stretch upstream of the dam was completely empty of life until 1993, when the state Bureau of Mines installed several lime-dosers. "It was like flipping a switch," he says. "The next year we were stocking trout and managing a fishery there."

The dosers are fairly rudimentary gadgets that pitch small doses of lime into the water at the outfalls of acid drains all along the river. Their effect is instant. "See how red the rocks are above the mouth of that creek?" asked Mike Dreisbach, with whom I fished last week. "Now look how chalky the water is below, and the rocks look normal again."

Dreisbach, who owns Savage River Lodge in Garrett County, occasionally sends guests on the river with guide Chris Moore. The three of us made the seven-mile drift from Barnum to Bloomington in an inflatable raft last week, fly-fishing along the way. It was an eye-opener.

For starters, it may be the prettiest stretch of river in Maryland, softly purling over rocks and rills and the occasional modestly challenging set of rapids. The banks are completely undeveloped and we saw just two other anglers all day. It's also the slipperiest river I've ever tried to wade, a side effect of all the lime dosing, which supports some greasy growth on the rock.

And finally, the Army Corps of Engineers, which operates the dam, allows just enough water through to float a raft in the deep pools, but not quite enough to make it through the rapids. I was deeply grateful we had Moore, built like the former college football player he is, to buck the raft over endless rocky obstructions by hand. He spent as much time out of the boat as in.

As for the fishing, it was good. Dreisbach promised we'd catch plenty of trout on dry flies and he wasn't lying. We did catch a couple dozen between us on small elkhair caddis flies, but they were all small fish, the biggest perhaps 10 inches. The longer we fished, the surer I was that some big fish lurked in the deep holes, and I finally persuaded Moore to let me try a sinking bead-head caddis suspended below the dry fly.

That produced a few more small fish, and finally on the last deep hole before the takeout, I took the dry fly off altogether, squeezed on some split shot and went down to the bottom, where on about the eighth drift I found myself fast to a gorgeous, 19-inch rainbow trout that fought long and hard in the swift current before coming to the net. That felt good!

As pleasant as the scenery is and as productive as the fishing was, the North Branch is not out of the woods yet, Dreisbach and Pavol say. They met late last week with Corps of Engineers officials, hoping to convince the government agency to let just a little bit more water down so anglers can float the river safely and more easily.

"Right now they're generally running at about 250 cubic feet per second," said Dreisbach. "If they could bump that up to 300 cfs several days a week, it would make all the difference."

The five outfitters working the river have formed a coalition, the Western Maryland Professional Guides Association, to help press their case. Says Pavol: "The Corps provides 1,000 cfs releases in April and May to support whitewater rafting outfitters; we're just proposing that they treat the trout fishing resource with the same respect they give to whitewater."

Pavol, who generally guides below the stretch where Moore goes, says 35 miles of fishable water lie below the dam, all of which would profit from slightly increased flow on designated days.

He also says the outfall from Mead-Westvaco must be continually monitored and could be further improved, and he also will press the Corps to moderate big, early spring water releases to drain down the lake, which he says are so strong they kill many trout.

Obviously, even success stories have lingering downsides, but the rebirth of the North Branch is an uplifting tale, overall. Larry Coburn and Charlie Gelso call this river the "Madison of the East," referring to the revered Montana trout river, in their "Guide to Maryland Trout Fishing." From a scenic standpoint, they are not far wrong.

Following is a list of trout-fishing guides working the North Branch of the Potomac:

Eastern Trophies, 571-213-2570.

North Branch Anglers (Ken Pavol), 301-387-5314.

Spring Creek Outfitters, 301-334-4023.

Sang Run Outfitters, 301-387-6726.

Savage River Lodge, 301-689-3200.

Fly-rodder Mike Dreisbach works the scenic North Branch of the Potomac River from a raft while guide Chris Moore mans the oars.