Jim Zoschg, Cameron County Conservation District Dead fish line the banks of the Driftwood Branch of the Sinnemahoning Portage Creek near the village of Cameron, Pa. This section is a little more than 15 miles downstream form teh train wreck site.

Fifty years ago, Green Drakes disappeared from Spring Creek in Centre County after someone from a Penn State University chemistry lab dumped cyanide into the water. The big mayflies haven't been seen there since.

"A bunch of us tried to reintroduce them by planting nymphs in the stream and duns in the foliage," said Dan Shields, of Lamont, Pa., who wrote about the incident in his book "Fly Fishing Pennsylvania's Spring Creek."

"We even netted thousands of spinners from another stream, but they never took hold. We tried for three or four years, but it was no use."

Although the recent train derailment and chemical spill on Sinnemahoning Portage Creek in Mc-Kean and Cameron counties was much bigger and more deadly, experts are cautiously optimistic that insects will rebound on what had been pristine, wild trout water, but predict a long, slow process.

"It could be years and may never be quite the same after something like that," said fly fishing author Charles Meck, who described Sinnemahoning Portage as one of the best Brown Drake streams in Pennsylvania. "It had a great, great Brown Drake hatch, the same one you'd find on Henry's Fork and Silver Creek in Idaho."

According to Penn State entomologist Greg Hoover, the return of Brown Drakes and other hatches will depend on what the main stem of the Sinnemahoning Portage can recruit from its healthy tributaries. "The hope is that insects will drift down, repopulate and help with recovery," he said. "In the case of Spring Creek, Green Drakes didn't exist on Logan Branch or any other secondary streams."

What's also essential is that plant life regenerate to the point it can support insects in the 35 miles devastated by the wreck that sent 40,000 gallons of sodium hydroxide, or lye, into soil and stream, killing thousands of wild trout and other species.

"That's the biggie -- getting algae and other healthy plants to establish, so that, once eggs are laid, immature insects have a source of food to maintain their populations," Hoover said. "Some of the pollution tolerant insects will return first, then, hopefully, the more sensitive species. It will be a progression. The time required for complete recovery is anyone's guess."

With some of the 31 derailed train cars still on site in the mountains near Keating Summit, "there are still a lot of unknowns, including the true extent of the damage," said Pennsylvania Department of Environmental Protection spokesman Kurt Knaus. "Until those cars are removed, we don't know how much sodium hydroxide soaked into the ground. You could have those contaminants leeching into the waterway for a very long time."

Prior to the accident, the upper reaches of Sinnemahoning Portage Creek had the state's highest quality water rating and four miles of Class A wild trout.

"I hope they hold Norfolk Southern's feet to the fire," said Bill Corringan of Rosedale, Pa.,who has a camp near the stream and mourns the loss of the 20-inch brown trout he has caught there for almost 20 years. "It was a beautiful stream, a diamond in the rough."

Norfolk Southern has been neutralizing the site with citric acid, and recently submitted a plan for how it will approach cleanup and long-term monitoring of the stream and surrounding land, but was told by DEP to present something more comprehensive once the site is cleared of debris.

"We still have a pollution event there. We still have a dead stream. We're still telling people to stay away," Knaus said.

While DEP addresses water quality, the Pennsylvania Fish and Boat Commission is developing a damage estimate that will reflect not just loss of wildlife -- including massive numbers of dead fish -- but projected lost recreational value to anglers such as Corrigan, and the impact on license sales and tourism revenue.

The Fish Commission is using an American Fisheries Society guidebook on the monetary value of fish and mussel kills that puts the regional average for replacing a 6-inch trout at 74 cents and a 12-inch trout at $2.77.

"That's just a start, and doesn't differentiate between wild and hatchery trout, and how much more an angler would pay to fish for a wild versus a stocked resource," said the book's co-author, biologist Andy Loftus. "Lost fishing opportunities, and the impact on a community and a state's heritage require a more intensive economic valuation, but one that is realistically defensible in court."

Fish Commission spokesman Dan Tredinnick expects it will take months to develop what he called an "airtight claim" against Norfolk Southern, given the evidence and historical data the agency needs to collect. As yet undecided is how best to restore wild trout to the upper reaches of the stream, which could include transplanting similar fish from other waters, using hatchery fingerlings, or simply letting trout migrate from tributaries.

Tredinnick said the lower six miles of Sinnemahoning Portage, which have always been stocked, could receive their usual allocation next spring.

"Sodium hydroxide isn't as long-lived as some other chemicals, so if the water quality issues are addressed, we might be able to stock for opening day," he said. "The water upstream is a different story. For that to be a self-sustaining system robust enough to support wild trout again will take generations of aquatic life."

Norfolk Southern has suspended without pay the engineer and the conductor who were operating the train, which was bound for Allentown from Buffalo, N.Y. They were charged with "excessive speeding and improper operation of the train," which derailed as it traveled down a steep grade posted for 15 mph, according to Norfolk Southern spokesman Rudy Husband.

The employees' names and other aspects of the investigation, including the results of drug and alcohol tests, were not revealed.

The public can review the DEP accident report at the Cameron County courthouse in Emporium, Pa. For more information, call 814-486-9353.