MAINE : Mount Desert Island has been attracting adventurers since 1007.

Thorvald Ericsson, the first European to set foot on Mount Desert Island, would have marveled at the scene: A couple riding chrome alloy bicycles with balloon tires on a pilgrimage through the woods.

What has become of his beloved island?

We wanted to find out on a heady trip back to an era when Maine was first explored by Viking adventurers.

The sun was playing hide-and-sneak on a cloud-laden day as we arrived at the Hulls Cove park entrance, mountain bikes in tow. Just the kind of weather we had hoped would greet us.

Summer days can be wet and moist along the Down East Coast, and rain would have turned the soft trails of crushed rock into a passageway of porridge. But the precipitation waited till the next day to drench the dense woods.

Only sunshine drenched us as we began cycling through a narrow path strung with a jungle of vines threatening to entangle us as we passed.

Our goal was to pay homage to the past, and Mount Desert is a monument to memories.

Though the charming coastal village of Bar Harbor, one of Maine’s most magnetic tourist attractions, would be no more than 15 miles from us at any point during the journey, we were pedaling in a wilderness, the likes of which attracted Ericsson in the summer of 1007.

Thorvald came to Nantucket Sound three years after his more famous mariner brother, Leif, discovered “Vinland.”

Also a bold sailor, Thorvald sailed north from Nantucket toward the rugged Maine coastline. He couldn’t miss Mount Desert Island, the highest point on the Atlantic Coast, but the enormity was not the island’s sole attraction.

Ericsson most likely discovered Somes Sound, which resembled his Scandinavian homeland. Somes, the only fiord in the continental United States, must have warmed his heart as he impetuously decided to make Mount Desert his permanent home.

But as an ancient Norse saga explains, Thorvald was killed by an arrow from Indians who inhabited the land. Maine was safe from European civilization for another 600 years.

Mount Desert got its name and distinction in 1604 when French explorer Samuel de Champlain landed there from the French province of Acadia, now Nova Scotia. In 1611 Father Pierre Baird of Grenoble, France, settled at Fernald’s Point, naming it St. Sauveur.

Some of the landmarks discovered by the Vikings and French have been left unobstructed. Such is the concoction of Mount Desert Island: Here is the Maine of deciduous forests, eclectic bird species, rustic inlets and rocky shoals sitting peacefully within sight and sound of millionaire mansions, pleasure-boat marinas, lobster restaurants and the curio shops along Main Street in Bar Harbor. For many who visit Maine, the latter are all they see.

We, however, had seen that Maine aplenty. The island’s rugged interior was appealing: the cleansing aroma of a brisk breeze off Frenchman’s Bay; the tantalizing scent of balsam wafting through the woods and the soft sounds of wind-rustled leaves, which still were a hue of green despite the approaching autumnal alteration.

Acadia is one of the nation’s smallest national parks, covering only 38,523 acres. But like San Francisco, the compactness makes it all the more accessible. Visitors roam the park by automobile roads and a spider’s web of intricate hiking, biking and horse trails that crisscross the terrain like quilt work. In winter these paths become the popular routes of cross-country skiers.

Some of the most renowned are the carriage trails conceived by John D. Rockefeller Jr., who from 1915 to 1933 spent $2 million building them. He was motivated by the introduction of the automobile to the island in 1915. It was a rude awakening to families who spent summers there seeking Maine’s sensual solitude.

Rockefeller liked the island’s natural beauty so much that he donated a third of the land for a national park. He also helped develop Acadia’s general plan.

His idea was to promote conservation. Rockefeller hired Fredrick Law Almstead, an architect who designed New York City’s Central Park, to build the carriage roads in 1915.

Almstead had two gate houses built in Tudor Revival style along the paths. Of the 16 bridges built, no two are alike. Little has changed, and visitors can take carriage rides through the woods.

We rode from Hulls Cove in the west to Northeast and Seal harbors in the east, an eight-hour ride. We encountered occasional joggers, bicyclists, day hikers, families and carriage horsemen. But mostly we were left to ourselves to explore the island in its pristine state.

The carriage trails are often wide, but traversing the island is difficult because of a series of roller-coaster hills. We were not surprised, considering that Acadia is a park of granite cliffs and hills that tumble to the sea; rural and rolling, it is a land of giants, such as 1,530-foot Cadillac Mountain, the island’s highest point.

In the spirit of Thorvald Ericsson, we crossed the island. Around a bend we encountered the sea. From our vantage far above Bar Harbor, we marveled at Frenchman’s Bay, a labyrinth of land and water. The colorful combination of green forests abutting the rugged rocky coast of the royal blue sea seems endless.

But as fast as it approached, the sea was behind us. Witch Hole Pond, as glassy and smooth as a bottle, emerged a mile down the trail. There, cormorants took command of the cool grassy waters. The adornment of wildflowers along the perimeters added a colorful sprite garnish.

Mount Desert, shaped by glacial action, is an isle of deep blue lakes protected by sheer cliffs. Riding around Beaver Mountain, we reached Eagle Lake and could see the geological transformation. Because a paved road also leads there, it is highly populated with picnickers, anglers and tourists.

We passed quickly and faced some of the trail’s toughest terrain along the walls of Cadillac and Pemetic mountains. It was hot, dry and dusty.

The hilly trail finally flattened, and we met another paved road, this time at Jordan Pond House, a restaurant on a crest that rises gently from the pond with a spectacular view. Most visitors drive there to wait in a long line for tea and popovers, an afternoon tradition.

From Jordan Pond we passed one of Almstead’s gate houses, now used by park rangers, and continued on the carriage trail, rolling through the woods as the sun sent its last shimmering light across the water. Colorful lobster buoys and sleek yachts bobbed in the harbor.

We helped a toughened old seafarer lower his rowboat into the water, then watched him glide off into the sunset with rhythmic strokes like a windmill.

Reaching Seal Harbor, we turned toward the interior along another carriage trail and headed for Hulls Cove. Cycling at dusk puts the island in a new light. We reached Jordan Pond as the last rays faded into darkness. We watched the still-life watercolor scene, then pressed on.

The night was clear and cool. The street-lamp light of the moon guided us from shadow to shadow, point to point. Seeing became believing. We were pedaling by radar. By then the park was stone-silent except for the eerie primal yodel of loons in the far distance.

Acadia National Park is 47 miles east of Bangor, Me., which is served by an international airport. Visitors can also fly into Boston. The six-hour drive from Massachusetts to northeast Maine is pleasant, particularly along U.S. 1.

Acadia has two campgrounds--Blackwoods and Seawall--in which reservations should be made through Ticketron during summer months. Eleven private campgrounds operate in the area, and Lamoine State Park about 15 miles away offers spectacular views of Frenchman’s Bay and less-crowded facilities.

A variety of accommodations, from plush resort hotels to bed and breakfast inns are in the region. On the island, Bar Harbor, Southeast Harbor and Northeast Harbor offer hotels; the chamber of commerce of each community will provide information. Ellsworth, Me., about 20 miles west of Bar Harbor, also has accommodations.

Once at Mount Desert Island, the nuggets of the Down East Coast are easily accessible by automobile. The only mainland segment of Acadia is on Maine 186, about 1 1/2 hours north of Bar Harbor at Schoodic Peninsula. A trip to the point makes a delightful day and offers dramatic views of Cadillac Mountain across Frenchman’s Bay.

Perhaps the park’s most remote area is Isle au Haut, which you reach by the shuttle-ferry Miss Anne.

The shelters, a five-mile walk from the town landing, are available by reservation with the park service. Sea cruises among the islands between Frenchman’s Bay and Baker Island also are offered.

Ferry service from Bar Harbor to Yarmouth, Nova Scotia, on the famous Bluenose involves a six-hour ride across the Bay of Fundy. The cost (with auto and two passengers) is about $120 one way.

For more information on the park, write to Acadia National Park, RFD Box 1, Bar Harbor, Me. 04069, or call (207) 288-3338.

For general information on travel to Maine, contact the Maine Publicity Bureau, 97 Winthrop St., Hallowell, Me. 04347, (207) 289-2423.