Charlie Fox is the dean of American angling. He is 69 years old. . Like Pepperidge Farm, Charlie Fox remembers.

"Big Spring Creek in south central Pennsylvania, near the village of Newville, used to be the finest brook-trout water in the country. You couldn't fish it enough; the trout were growing faster than the fishermen could take them out."

But what so often happens happened to Big Spring. Man and the environment - in this case the lovely orange-white-and midnight-blue native brook trout - came face to face over who ruled the creek, which is the third-largest springs in the world.

In the 1950s a commercial hatchery and a dam were built on the creek. Resulting excrement and siltation choked the spawning grounds used by the wild trout. Soon the population of genetically wild fish, as opposed to stocked fish, declined. Charlie quit fishing the creek 15 years ago. "I loved that creek," he says "and I want to remember it like it used to be."

Anyone who has ever told a fish story knows that memory is part of fishing. To recapture memories and to offer excellent fishing to future fishermen, in 1970 the Pennsylvania Fish Commission bought the upper three miles of Big Spring Creek, including the old commercial hatchery and the contaminated spawning grounds. The commission immediately closed part of the water for study purposes. The question was whether a nationally famous brook-trout fishery could be restored.

A couple of weeks ago the commisson apparently decided that it could. If successful, it will be the first major restoration of a signifigant brook-trout population in the country.

The problem is that brook trout are delicate. They don't get along with pollution, with forests being cleared, with farmers' ferilizer or with anything that doesn't meet their criteria of a pristine environment. They are native only to cold mountain waters and a few spring creeks in the eastern United States and Canada, and 300 years of lumbering, farming and industry have restricted the remaining wild trout to the few tiny pure mountain streams lelft. The result is that most trout fishing today is for ignorant, docile, hatchery-reared fish that are sexually impotent and capable of living in the natural environment for only a few weeks. It is called "put-and-take" fishing and is but a vague image of what American streams once offered.

The restoration project is headed by Dick Snyder, a trout and salmon biologist.During the years that the stream was closed for study, rainbow and brown trout propagated and grew to enormous size. In 1976 the closed section of the streat was opened to allow the killing of large trout only, on the theory that the rainbows and browns would be eliminated before they reproduced or crowded out the smaller brook trout. Rainbows and browns provide excellent sport, but what is at issue on Big Spring Creek is the rare opportunity to restore a sport fishery that has been virtually lost.

Snyder and a crew of fishery employees have just electroshocked a mile and a half of Big Spring to separate the rainbows and browns from the remnants of the brook-trout population. More than a thousand rainbows and browns up to 24 inches were moved below a fish gate near the midpoint of the commission's property, all of which is open to fishing. The upper mile of the creek, including the best remaining spawning grounds, is now left to the brook trout. Snyder reported that during the shocking several 15-inch-plus brook trout were among the approximately 300 native brook trout recovered. Few brook trout today reach 15 inches. They are prized not for their size but for what they symbolize - wildness and purity.

The commission is intent on restoring the fishery. No brook trout under 15 inches can be kept at Big Spring, and should you catch one of those "keeper" fish, consider putting him back alive. You can catch him twice, but you can only eat him once.

Will Charlie Fox ever fish Big Spring again? He doesn't think so. He fears that a recently built state hatchery will contaminate the eggs of the fledgling population despite efforts by the state to filter out all wastes.

"The Fish Commission is a bunch of young fellows, better than ever before," he says, "but none of them ever saw the creek in its glory days. You used to not be able to stick a rod out without it being over spawning fish."

Charlie knows that memories are in the blood of fishermen. They are his hook.