On the South Island of New Zealand, one simply tramps in "the bush." Though the bush may be anything from the glacial fiordlands of the south to the coastal rain forest, "tramping" remains a homey Kiwi sport. Even the word is insouciant, untechnical and, unlike "backpacking," it doesn't belabor the obvious.

The South Island is nearly as large as California, and has as wide a range of climate and terrain. California has one thing, though, that the South Island doesn't: people. Fewer people live on this wild island than live in the Los Angeles suburb of San Bernardino. There is a single modest freeway in New Zealand, and it's in Auckland, on the tame North Island.

This remoteness is one reason that access to the national parks on the South Island is mostly limited to trampers. You bring what you need and you walk in on any one of thousands of tracks, or hiking trails, in the bush.

I hadn't backpacked very much, perhaps because I didn't like being reminded of what I had to carry. But somehow the word tramping didn't have such onerous connotations. So I borrowed the gear and headed for the South Island, specifically to Nelson province, which holds two splendid parks -- one alpine, one coastal -- each only a half day's drive from the other. See NEW ZEALAND, E4, Col. 1 NEW ZEALAND, From E1

In my hemisphere the days were growing shorter, thcanyons, many times crossing a waterfall at its furthest reach, and on it the hiker enters its rhythm: from the headland, with its prospect of beach and offshore islands; into the rain forest, where the sound of falling water overwhelms the sound of the surf booming below.

Inland the native beech forest also immerses the trail. The tiny leaves of the beech compose a translucent green atmosphere overhead, especially at twilight. Beneath that canopy grow strange and ancient trees -- the local Rimu, Rata and Nei-nei -- and prehistoric-looking tree ferns. Then there are the rain forest creatures: the creepers, the perchers, the vines and moss, called spleenwort, lawyer vine, supplejack, sphagnum. Black fungus covers some of the beeches -- the stuff grows on honey exuded by a mealybug in the bark, and many of the trunks are black, as if charred by fire.

Before human beings came to New Zealand, it must have been a bird's paradise. Except for bats, there are no indigenous mammals here, and no snakes. Monarch of the island was a 14-foot-tall bird called the moa, made extinct by the first wave of Polynesian pioneers, who set fires in the moas' habitats and panicked them onto sand spits, where they were easy prey.

In the dense canopy I could not often see the birds, but many times a birdcall would bring me to a stop. The bellbird has a song of some impossible number of notes, rising and falling -- and then as a kind of encore adding a phrase to its answering call. The tui's song is so beautiful that the Polynesian natives called the Maoris ate the birds' vocal chords to improve their own voices.

Huts on the walking tracks of New Zealand are very basic accommodations. The water runs, but often only in the streams. The huts have bunks with mattresses, a stove or fireplace, and little else. When I was there, the guests were mostly young and international. Some had tents and others just slept in the open. I did, too, looking far up into a sky full of strange stars.

Ten miles from the trail head, and two days in for most hikers, the Coastal Track reaches Awaroa Inlet, one of several tidal estuaries on the route. If you arrive, as I did, at high tide, you wait for a few hours. The inlet extends two or three miles inland, and at low tide almost all of that area, most of it covered with clamshells, is drained. The tide drops the water level eight to 12 feet here, going out like a river twice a day, and coming back in rich from the sea, feeding a community of creatures who wait for the tide for their living.

And a huge population it is, in this fertile bay, in ranks and colonies, depending on their needs from the sea. Mussels and barnacles grip the rocks at the surf line, fish and a city of shell life crowd the protected inlet. Snorkeling in the clear water, I found acres of dark clams on the bottom, and schools of fish, each species gradually larger toward the inlet's mouth.

On the third day, the trail reached Totaranui Beach. This is a real beach, a mile-long stretch of sunny sand at the end of a long walk. It is also the pickup point for a private launch service -- which cruises back around the offshore islands to Marahau.

The human culture of the South Island seems vigorous. South Islanders are a tough people, happy and tidy. Many pubs have a sign outside that says "Tidy Dress Required," and inside there will be a man with a guitar singing some happy and outlandish song like "Lollipop, Lollipop."

The pubs are brown affairs, with good Kiwi Brown Beer -- ask for "a handle of the brown." The food is likely to be called "solid fare" in the travel guides, which means your choice of fish and potatoes, lamb and potatoes, ham and potatoes or beef and potatoes.

My favorite pub in the Abel Tasman Park area is a place called The Rat Trap, also known as the East Takaka Hotel, on the western slope of the park's marble immensity called Takaka Hill. Built in 1903 for the then-flourishing mining industry, the place posts winners of the local snooker contests, and uses an old car tire to frame the dart board. For some reason there are a number of snapshots of ruined trucks that have failed to make the curves on the hill above. A sign on the back-room door says "Strictly Private," and there is the traditional tethered goat keeping the front lawn tidy. When people come in, the barkeep says things like "Just popping around, are you?"

Back from four days in the bush, I treated myself to a British bed-and-breakfast place in the small town of Nelson, a place called the Seafield with flowers all over -- grapefruit-sized roses in the front yard, bouquets on the wallpaper, sprays on the table. Breakfasts, I found, are the best meal in the country, and here was the best that I found. It's a huge meal, proceeding in two solemn courses -- first cold, then hot -- and distinguished by large and firm fresh eggs. Plus the ceremony made in New Zealand over breakfast helps to prepare one for the feast that happens at tea.

The Rotoroa Lodge in the Nelson Lakes National Park is one of those Hemingwayesque places, with deer heads protruding from the walls and angler-guides for hire for the famous New Zealand trout fishing. The place is perfect for hikers who, if they have to hit the trail, wouldn't mind hitting it after roast beef and claret and a good night in a good bed.

The lodge sits at the end of a long glacier-carved lake, at the other end of which are granite peaks, streaked even in summer with snow. They are the Spensers, the northernmost peaks of the craggy chain that forms the spine of the island.

The fishing boat from the lodge took me 10 miles into the mountains, to the trailhead at the far end of the lake. From there, I started up the Sabine. Twenty kilometers up is the azure pool called Blue Lake, where a hut sits beneath the stony crown of Mount Franklin, at 7,600 feet the highest peak in the range.

The first four hours aren't difficult walking -- silt in the river valley has built meadows here, grassy places the river rushes around. Four hours out -- as is the rule in New Zealand's parks -- there is a hut, across the river via swinging wire-and-plank suspension bridge. The map indicates that the next hut is much closer than four hours, but only if one disregards all those tiny lines indicating altitude. The track gets steeper immediately, climbing the rooty banks of the river and traversing wide boulder-fields of scree.

Though the walking's harder, the river is wonderful up above. It's a white roar around the boulders, and where it gathers a current it is ice blue and fast. Its tone grows sharper and louder as one ascends to the bushline (as the Kiwis call it), into a high wide basin where from the granite cliffs pour three waterfalls. The final hour of the walk is a tough climb through the last vegetation -- a stand of beech that, when I passed through, had been pushed over and broken by avalanches during the previous winter.

The Blue Lake Hut sits just beneath a ledge out of "King Kong." A glacier has cut a shelf between two peaks on the mountain, beneath which a cavern opens up high on the cliff face. Over the ledge runs Moss Pass, which on that summer day would have required an ice axe and crampons.

Unlike the sea, the mountains insist on solitude, even when one is not alone. At Blue Lake, I shared a hut with another hiker, and though the hut on the beach at Awaroa had been filled with voices, here at the top of the country we exchanged only a greeting and a goodbye in 18 hours together. The intervening silence was not like being tongue-tied at a party. That evening we just sat on the step, watching the light leave the rock face until the high patches of snow seemed to hang in the dark across the canyon. There was no need to say anything.

The South Island is so beautiful and various that it gives the traveler some interesting problems, like which splendor to see and how one shall ever leave. I suggest consoling yourself by leaving the South Island slowly, on the ferry, which departs northward toward the North Island through the fingers of land around Queen Charlotte Sound. You may settle in the sun on deck, and in the manner of a traveler pose luxurious dilemmas to yourself. For instance, which was better, the ocean or the mountains?

Though the real hike, up into the Spensers, toughens a traveler, one may decide to prefer the sea -- old home, that it is, to the astringent peaks, though they are thrilling and visionary. Deciding the argument isn't the main thing, though. After a trip to New Zealand's South Island, one may simply wish to entertain the question for a long time.