For centuries, cooling fogs from the sea have wrapped a protective cloak around the sun-shy coast redwood trees of Northern California. The trees thrive on the moisture, but be warned. A visit to the state's magnificent Redwood National Park can sometimes get a little drippy. The fog, though, is very much a part of the beauty.

"Monarchs of the mist," these coast redwoods have been called, a catchy description that attests both to the frequent presence of fog, especially in summer, and to the coast redwoods' most striking characteristic. They are the tallest trees on earth, soaring skyward as if to break free of their wrap for a few hedonistic moments of warming rays.

Height, whether possessed by humans or trees, is imposing, and you stroll among these 300-foot giants with a certain awed respect that they almost demand. Many visitors liken a redwood grove -- mighty trunks and overhanging branches forming a forest room around you -- to the interior of a cathedral with its lofty arches and similarly muted light. Albeit, a cathedral with a very leaky roof.

The comparison is quite apt. We entered the forest as gawking sightseers, drank deep of its mystique, and emerged a while later as reverential disciples.

Our conversion began on our first morning in Redwood National Park -- a foggy day, not surprisingly, which prompted us to start our exploration with an easy hike to the park's most popular attraction, the Lady Bird Johnson Grove. The grove is so named because of the former first lady's work in behalf of outdoor beautification. The natural tribute is as appropriate as it is impressive.

Looping through the hillside grove is a mile-long nature trail -- the kind where every dozen yards is marked with a signpost pointing to a natural phenomenon. Outdoorsmen often belittle nature trails as a tourist intrusion on the wilderness, but I can think of no better way to get to know these coast redwoods than to read and reflect on the brief lesson each of the 19 way-stops yields. They even instruct in how to compose haiku, the Japanese form of poetry expressing self-awareness in nature.

The fog was light that morning, more a haphazard swirl of cloud in the high branches above than an eye-blinding cover, and sunlight frequently skipped ahead of our footsteps. I could, by tilting my head straight backwards, occasionally spy the top of a tree suddenly emerging from the mist. My face, meanwhile, was quickly washed by the moisture falling like raindrops from the thick branches overhead.

The needle-strewn path, spongy-soft from the dampness, winds through a garden of green mosses and ferns that flourishes at the feet of the redwoods. The guideposts directed our eyes to orange salmonberries, luxuriant rhododendron and masses of tiny, cloverlike redwood sorrel that carpet the ground. Huge branches, shorn by winter's ferocious storms, were a reminder of the dangers of a high wind in this forest. Early on, pioneers for good reason dubbed these fallen branches "widowmakers."

At an early hour, we were the only visitors, and very quickly the quiet and the solitude had an effect. We slowed our pace and stopped our chatter. We carried day packs with snacks, but a picnic somehow seemed inappropriate. We were, I realized, instinctively slipping into the polite respectfulness most tourists display on entering a cathedral. If the Lady Bird Johnson Grove was, indeed, a great church, for a few minutes we became its vocal archbishops.

As each signpost appeared, we took turns reading its message aloud, aiming our words with sermonlike fervor to the wisps of mist darting around us. It was part game, part joyful exhilaration -- a sort of spontaneous outburst at the wonder around us. And we paid attention to those minilessons.

"Feel the bark of this Douglas fir," one of us preached, "and compare it with the coast redwood behind you." At their bases, the two trees -- they share the same terrain -- seem similar. But the bark of the redwood is furrowed in long perpendicular lines; the furrows of the Douglas fir are irregular. From that moment on, we could distinguish between them wherever we hiked.

"Some trees may live 2,000 years," I recited to a pair of passing blue jays, "and many fine examples reach heights of 300 feet or more, as tall as a football field is long." A slender banana slug, inching across the trail, also may have heard but gave no indication. These little yellow creatures are very much at home in the damp forest.

"Redwood trees exchange many gallons of water each hour with the surrounding air," my companion read on. "Without the protection of fog, and the 85-inch annual rainfall, these giants could not replace their moisture losses." We were, by now, ardent believers. We marveled at the forest and accepted the persistent fog with understanding grace.

And at Signpost 19, we appreciated the final message, an anonymous example of haiku:

It is not easy

to leave this cool green garden

for the dusty road. Redwood is a relatively new national park, created by Congress in 1968 to protect a number of magnificent coast redwood groves threatened by logging, a big business in Northern California's forests. The park had a troubled birth, opposed by many local loggers who feared it would destroy their livelihood. Gradually, however, many nearby residents have come to view the park's redwoods as a valuable heirloom to be passed unharmed to future generations. The National Park Service, meanwhile, has undertaken a massive forest restoration project, replanting thousands of acres of coast redwoods cut in earlier years.

The coast redwood, a rare tree, grows only in a narrow strip of land along the Pacific Coast that extends about 400 miles from southern Oregon south to Monterey, Calif., just south of San Francisco. The trees stand a bit inland, away from the sea, mostly in the coastal mountains below 3,000 feet. Here they take advantage of a temperate climate, heavy winter rains and the fog that rolls up the mountain slopes.

The coast redwood differs greatly from its cousin, the giant sequoia redwood of central California, which prefers the higher, dryer slopes of the Sierra Nevada. The trunk of the sequoia grows much thicker and its bark has a lighter, more reddish hue. The sequoia, in a way, is built like a squat, bulky football star; the much taller coast redwood has the slender, streamlined shape of a basketball whiz. A third rare redwood is found in China.

As early as 1902, efforts to save many important coast redwood groves met with some success, and Northern California is agreeably dotted with fine redwood state parks and other preserves. The new national park, about a 50-mile long segment of Redwood Country at the northern tip of the state, provides sanctuary for the very tallest of the coast redwoods, reaching 367 feet and still growing. A prime reason for the push to create the park, they are clustered on Redwood Creek, another prime destination for park visitors -- though to reach them you have to do some hiking.

Redwood National Park, which totals 106,000 acres, is a wonderful blend of rock-strewn beach, thickly forested mountains and high, grass-covered prairie -- all within a few miles of each other and stripped, like the park, from north to south. This is good country for hikers and campers. Some trails descend from deep, fern-laced woods to isolated sea coves, outlined by wide stretches of sand. Many are short hikes of an hour or two. Or you can hike the length of the park along the Coastal Trail.

You can explore tidal pools at Enderts Beach, fish in the surf for red-tailed perch or watch for passing whales -- often visible just offshore from cliff-hanging Coastal Drive. Herds of Roosevelt elk can be seen at Gold Bluffs Beach and Boyes Prairie. You can paddle a canoe down the fast-running Smith River or fish the Smith and the Klamath rivers for salmon and trout. Locals advise swimming in Smith River and Redwood Creek rather than in the cold, turbulent Pacific Ocean. The rivers are much warmer -- and if you go far enough upstream, you can escape the chill of the summer fog.

Still in its youth, Redwood is very much a park in transition. When it was established in 1968, initially only 58,000 acres were set aside, and half of those already were protected by three state parks -- Jedediah Smith, Del Norte Coast and Prairie Creek, all still managed by the state park system. The original acreage also included a ribbon of land -- "the Emerald Mile" -- fringing each side of Redwood Creek leading to the Tall Trees Grove. Unfortunately, the high, surrounding hillsides above the tall trees were at first excluded.

"What Congress created in 1968 contained good samplings of trees," says Robert Belous, a spokesman for the park, "but it was not a self-sustaining system. All the redwoods upslope and upstream were available for cutting. And they were cut, and at a pretty good rate."

The result was that the erosion from the hillsides above was endangering the Tall Trees Grove. Conservationists went to work to add 48,000 acres of the watershed to the park, but it took them 10 years to win congressional approval. In that 10 years, says Belous, loggers had cut 75 percent of the trees in the new acreage. "Most of the land looked like a war zone."

Obviously, the threat of erosion remained a problem. As part of the park's expansion, Congress also voted $33 million to rebuild the forests on about 30,000 acres of cut-over land, a program dubbed "the Redwood Renaissance." A particularly troublesome task has been erasing more than 200 miles of logging roads and reshaping the slopes so that rain runoff can return to its former natural channels.

At the same time, says Belous, "We're going hell for leather planting redwoods. We've got thousands of seedlings on prepared ground that are a year or two old."

The program, which has drawn conservationists from as far away as China, is expected to be about 90 percent complete by 1991, says Belous. "It's a matter of putting the land back on its feet to park standards -- to so mimic the original natural scene that an expert who comes through can't spot the scars."

One success is that the Tall Trees Grove appears to have been saved. To see the tallest trees, backpackers can hike the 8.2-mile Redwood Creek Trail to the grove. In the summer, a park shuttle bus system takes visitors to within a half-mile of the grove. Some hikers ride the shuttle bus to the grove and then exit along the Redwood Creek Trail, a fine day-long trip.

Another cause for cheer is that 50-pound salmon have returned to Redwood Creek now that it is no longer heavy with silt. Nowadays, says Belous in understandable pride, "Travelers come to the park to be beguiled by the redwoods, and they may end up being smitten by the restoration."

Belous has something of a point. The restoration does appeal to one's sense of justice, of a wrong being righted. That's an intellectual appeal. But the centuries-old trees -- the survivors -- they can tug at your heart. Each of these giants is an individual, and if you pause to study one -- which I recommend -- it takes on a personality. A crippled old fellow that impressed me has been much battered by fire, wind and lightning. Somehow, though, it manages to thrust new shoots into the sky to keep alive. Fortitude under duress is an admirable trait even in a tree.

On the edge of the park, near the Lady Bird Johnson Grove, is a lumber mill in full operation -- a reminder that logging goes on. On weekdays, guided tours are offered showing how Douglas fir and redwood trees (not from the park) are shorn of their bark and trimmed into planks in a matter of minutes.

Certainly we need lumber, but so soon after my walk in the woods the buzz saws seemed almost ghoulish, and I couldn't help but think of the piled logs as victims of some horrendous massacre.

Those unpleasant thoughts soon evaporated when we returned to the woods to hike among the redwoods along Redwood Creek. My delight in the trees and their setting was restored by yet another signpost at the trailhead. Somebody at Redwood National Park has a flair for poetic expression. We paid heed to this sign, too, and we were rewarded.

Listen to the "woods music," it urged. "The mighty redwoods creak and groan as they sway in invisible treetop winds. Dragonflies clack, mosquitoes whine and streams gurgle in sun-drenched forest clearings." We listened and we heard. And, by now, the fog had lifted and the sun shone bright.