PARKER, Pa. -- Jeff Knapp launches his 16-foot jet boat into the Allegheny River in this tiny city 75 road miles north of Pittsburgh.

The ramp belongs to a half dozen cottagers whose pontoon boats are moored nearby. Their small vintage trailers are perched on a bluff overlooking the free-flowing water, catty-corner from cedar-sided mansions and A-frame chalets where once there was only wilderness.

"Property you couldn't give away 20 years ago is now going for millions," says Knapp, who lives downriver in Kittanning. He fishes the Allegheny several days a week and became a licensed guide earlier this year. "A lot of people stay up here on weekends, but I'd say just 5 percent of them fish. Most of them like the wildlife. They like looking at the water."

Fog is still lifting from the river at 8 am. The water is high and dirty from so much recent rain. We are just below where the Clarion River dumps in under an old railroad bridge that is now a bicycle trail.

"I've nosed up into the Clarion," says Knapp, "but the water quality isn't as good. I've never gotten bass of any real size there."

He prefers the Allegheny, whose riffles, runs and rocky shoreline can yield a bounty of smallmouths at this time of year.

"When water gets warm -- 75, 80 degrees -- bass can be anywhere, but I generally start shallow," says Knapp, tying on a white swimbait. "They'll often be sitting within 3 feet of shore. The big fish will hold amazingly tight to shore in warm weather. It's a great ambush point for them."

As if to prove it, Knapp hooks a 4-pound smallmouth on his third cast to the bank. The fish is a deep bronze hue with subtle markings. Knapp has caught two other 20-inch bass, but in December. Late fall and early winter are the best times for boating trophy sizes, he says. "Summer is more of a numbers game."

We work the shoreline, releasing a dozen more bass as the sun burns away the fog to unveil a cloudless sky, and then motor to a grassy island in the main channel and cast to the vegetated edge where fish are known to hold.

With the same bait, Knapp releases a 32-inch northern pike.

"You can see how the grass strains the sediment, how much clearer it is where the weeds are," Knapp says. "When you're in really dirty water, you like finding areas like this. They create zones where fish can see your bait better."

If he were taking clients for walleyes, Knapp would cast to runs in the main channel.

"Walleyes like it a little deeper when water gets warm," he says. "They like the heavier riffles in 2, 3, 4 feet of water where there's rocks that break down the current, and give them ambush points."

But smallmouth bass are his favorite. And while he also guides on Keystone Power Dam, Pymatuning Reservoir and Lakes Arthur and Kahle, the Allegheny is his first choice.

"You just get so spoiled fishing the river," he says. "For the size of the water, it doesn't get much pressure. You can be out here on a weekday and not see another boat."

There are two public launch sites: one at Parker that the Pennsylvania Fish and Boat Commission refurbished this year; another at Emlenton. The middle Allegheny also draws canoeists, kayakers, and wildlife watchers. Around Parker, the deepest water can be just over 3 feet in summer, making a jet boat almost essential.

Parker is above East Brady on a long free-flowing section of the river with no dams. It continues for 87 miles to the Kinzua Dam. The entire stretch was given Wild and Scenic status 16 years ago, as part of a Congressional effort to preserve America's most pristine waterways.

There aren't many left, according to Darrin Crabtree, a biologist with the Nature Conservancy.

"The middle Allegheny is one of the last remaining examples of the kind of rivers that once existed in the Ohio Basin, and are now gone."

While it is home to more than 100 species of mussels and fish, he says, "in particular, it provides habitat for rare mussels and rare fishes that have been extirpated from a lot of their original ranges across multiple states."

A huge cache of rare Northern Riffleshell and Clubshell mussels was discovered in recent years during bridge construction near Foxburg. Federal diver-biologists tagged the mussels for monitoring and moved them one by one to an upstream location in work that concluded this past spring. The presence of mussels is an indicator of clean habitat. So, too, is the natural muskie reproduction that pro guides Howard Wagner of Fombell and Red Childress of Warren believe occurs in the middle Allegheny.

Anglers sometimes spot bald eagles nesting along the river, as well as ospreys, mink, beavers, black bear, deer and, in fall and spring, an abundance of waterfowl, from mallards to less common species, such as canvasbacks, goldeneyes and redheads.

While Crabtree says the river isn't under imminent threat of environmental impact, his agency and others, including the Western Pennsylvania Conservancy, are working to "keep it ahead of the curve," especially as near-shore development continues. The Western Pennsylvania Conservancy and other partners have protected 18 islands and thousands of acres of riparian land.

The river's forage -- shiners, suckers, chubs and crayfish -- makes for healthy numbers of bass, says Knapp.

"I've had 100-fish days out here and I've caught smallies down to 37 degree water temperatures, which is pretty much pushing the limit," he said.

Anglers unfamiliar with the free-flowing Allegheny will find it's a much different river than the navigational pools in the lower reaches approaching Pittsburgh, says Knapp.

"It can be easier to read, especially in summer, when features jump out at you," he says. "It can also be more challenging. There's a lot of water, a lot of options, and it's dynamic, always changing."