For me, there was a time when the two- to-three-hour drive over the Florida Keys on the narrow Over seas Highway on the way to Key West was little more than a frenzied blur of Jimmy Buffett tapes, green tropical waters and one tourist trap after another selling the same tacky T-shirts, plastic flamingos and watery chowder with leather-tough conchs. Key West was the gold ring and nothing in between seemed to matter -- indeed, nothing in between seemed worth mattering about.

It took a collision between two of those gargantuan touring living rooms known as Winnebagos to change my mind. The ensuing pileup sprawled over both lanes of U.S. 1, leaving long lines of traffic stretching as far as the eye could see. I swung off the highway looking for a back road that would take me around this madness and coasted right back about 30 years to a gentler, more authentic Keys experience.

Since then, each time I make the drive from the mainland to Key West I like to spend at least a couple of days exploring the side roads on the tiny islands linked by the 113-mile Overseas Highway. By the time I get to Key West, I feel much more assimilated than before, much more attuned to the strange island blend of inertia, eccentricity and adventure that permeates these places.

On a recent trip through the Keys, I exited U.S. 1 at the edge of the mainland, just beyond Florida City. There, at the Last Chance Beer and Gas Station, I turned left onto the Card Sound toll road and prepared to enter the Keys via the undeveloped wilderness of north Key Largo.

I was on the Card Sound Road for only a few hundred feet when I passed a thick grove of wild royal palms. On one, a hand-painted wooden sign with an arrow and the word "God" pointed southward, in my direction. Already the trip showed promise: My pursuit of off-road tropical whimsy seemed to dovetail with some plywood missionary's vision of salvation.

Here, fluffy, exotic Australian pines hug the roadside, giving way first to thick mangroves, and then to a stretch of nautical funk -- ramshackle fish houses, a sprawl of crab traps and an array of half-sunken work boats. Rock-and-roll blared from a dilapidated wooden building whose hand-painted sign advised: "Fride Fish. Stone Crabs. Conch Fritters. Under New Management."

I ventured in. There were no windows, but the wide, shedlike doors had been opened to the bright tropical sun. The ceiling was adorned with several hundred baseball caps. A pool table with a thin coat of limestone dust from the roadside occupied one corner. Behind the bar, a young woman in a halter top swiveled on a stool. A ceiling fan moved the briny air around the room.

Outside, a few hundred feet to the east, a towering Keys cactus framed the doorway to another restaurant. Alabama Jack's, with a pleasant outdoor deck next to the canal, seemed a little more promising than Fride Fish, and I wandered over. Settling back on the deck with an iced tea and conch fritter, I quietly exhaled deep bursts of mainland anxieties.

Back on the Card Sound Road, I paid the $1 toll and drove onto the 65-foot-tall Card Sound Bridge spanning Barnes Sound to the south and Card Sound to the north. The last remaining crocodiles in America are found among these broad estuarine bays. From atop the bridge, you can get a good idea of how all the Keys once looked around the time pre-Columbian Arawaks hunted and fished here. If a group of Miami developers had been successful in the 1970s, I'd be looking at wall-to-wall condos instead of the native tropical hardwood hammock that is now here.

Once on north Key Largo, I passed a number of unmarked paths leading back through the jungle of gumbo-limbo, pigeon plum and mahogany. On other visits, I've stopped for short hikes, trekking back through the steamy foliage that is dotted with wild orchids. If you take the time to examine the limestone boulders scattered around here, you'll see that they are actually chunks of ancient reef with fossilized imprints of brain and elkhorn corals, still clearly defined after 100,000 years.

But reality soon intrudes. If you continue south over Card Sound Road until it merges with U.S. 1, you'll enter the 20th century smack in the middle of Key Largo, in the form of dive shops, Burger Kings and Winn-Dixie shopping plazas.

A person can tolerate only so much of this sort of thing. At Mile Marker (MM) 100, not long after I passed a large bronze sculpture of an alligator on its hind legs with a radio pressed against its ear, I turned east off U.S. 1.

I headed for 1313 Ocean Bay Drive, where the white concrete building and wooden docks of Key Largo Fisheries line one side of a small cove on the Atlantic. Crabbers and fishermen tramp in the back door with crates of dripping-wet seafood to be sold to wholesalers and retail customers who come in the front.

Although the seafood is peddled to go, the stone crab claws are nearly always cooked before they are sold. As a result, you can fill up your cooler with the bright red claws with the rich, white meat and crack 'em later when hunger beckons.

While here, you can amuse yourself inside the screened porch of the Pilot House restaurant, on the other side of the cove at 13 Seagate Blvd. Here, stone crabbers and lobstermen motor up to the docks and off-load their catches, just as they have for decades in the Keys.

Back on the Overseas Highway, cars of day-tripping Dade Countians line the road. Go as fast as is legally possible; soon you'll be safely on the bridge over Whale Harbor channel and down onto Upper Matecumbe Key.

As you head south, keep a lookout for MM 78. Between it and MM 79 is a brown state park service sign on the right side of the road, announcing the boat shuttles for Indian and Lignumvitae keys.

Lignumvitae, named after the tropical hardwood tree, is just offshore in the Gulf of Mexico. It is probably the best example of virgin tropical forest still remaining in the Keys. Rare Florida banded tree snails, decimated by development and collectors elsewhere, still thrive here, along with lots of tropical plants your ranger guide will happily point out during the three-hour walking tour.

If Lignumvitae appeals more to naturalists, Jacob Housman's Indian Key will stroke the imagination of the archaeologist and historian. Situated oceanside less than a mile offshore, Indian Key in the 19th century was once home to a bustling little pioneer community with its opulent Tropical Hotel, a bowling alley, bar, post office and a number of small homes.

New Yorker Housman, the archetypal Florida pioneer, antagonized both salvors on Key West and Indians in the Everglades. Finally, an Indian attack during an early summer morning in 1840 destroyed most of the settlement. Today, park rangers lead small bands of visitors over the remains of the streets, past crumbling cisterns and stone foundations.

Down past Lower Matecumbe is Long Key, some seven more miles south. Once a private fishing club for wealthy sportsmen, Long Key is now home to a state recreation area with 60 well-shaded campsites, beaches, wooded trails and even an observation tower.

On its Atlantic side, this boot-shaped island offers some of the best shoreline bonefishing to be had in the Keys. A nature trail winds back through the thick hammocks, over boardwalks and out onto a white, sandy beach. You can snorkel, fish or crack those stone crabs at picnic tables under the palms.

But I wanted a different kind of Key experience, so I headed for the Lime Tree Bay Resort and its promise of old-time, laid-back pleasures at MM 68.5, just a bit north of Long Key.

Its rooms -- shrouded by thick crotons and giant rubber trees -- are just a few yards from green Gulf waters.

Funky but clean and exceedingly comfortable, Lime Tree is the perfect antidote to the fast-lane chain developments that dominate the Overseas Highway.

Decisions, decisions. Woven hammocks are strung between palms, lounge chairs are scattered about under a wooden gazebo, and a small swimming pool sports a hot tub. Scuba-divers are shuttled offshore for an extra fee, and a nearby concession rents daysailers and motor boats.

I could have spent a week at Lime Tree, but I hit the road again, in search of the abandoned limestone quarries that offer roadside diving opportunities. Mined to shore up the Overseas Highway years ago, many of the quarries have today become filled with sea water.

I stopped alongside the road at MM 56.5 and looked for an opening that would take me down to a Gulf-side quarry here that measures several acres in size. Here, an entire wall on the north side of the quarry is alive with all manner of invertebrate sea life.

At 25 feet and more in depth, the quarries are big enough to use scuba gear. But since there are no currents or wave action, they also are safe enough to explore with just a snorkel and mask. The great beauty of the quarries is that I would have had to go hundreds of yards offshore by boat to see many of the same species. The Gulf-side quarries, including another one just south of the Bahia Honda channel, are usually situated on unrestricted private land, or on "common bay bottom." Either way, there are no "interpretive tours"; don't dive alone, and remember that your dive safety is entirely up to you.

No off-the-road trek to the Keys would be complete without at least one truly indulgent experience. Little Palm Island is a private resort about a mile offshore of Little Torch Key at MM 28.5. It's a chance to escape from reality, Keys-style of course.

When it was used as a retreat and fishing camp for presidents -- Franklin Roosevelt, Harry Truman and John Kennedy all spent time here -- the five-acre Little Palm was mapped as Munson Island. Once a primitive outpost that relied on generator electricity, the island today is fully wired. But in an effort to sustain the notion of escaping mainland pressures, Little Palm provides neither telephones nor television for its guests. (A communal radio telephone is available for those who just can't do without.)

The feeling of escape begins the moment guests step aboard the island's ferry for the 15-minute shuttle from Little Torch Key. The island is dotted with 14 large "huts"; thick tropical foliage and palms ensure privacy. At a spit of white sandy beach on the windward side of the island, some guests sunbathe in the buff -- an activity that brings small private planes in to circle for an aerial leer. After a stint at Little Palm Island, you ought to be able to segue into Key West's odd and wonderful tropical rhythm without missing a beat.

Bill Belleville is a writer living in Sanford, Fla. His book "The Manatees' Sigh" will be published next year by the University of Florida Press. WAYS & MEANS

INDIAN, LIGNUMVITAE KEYS: Park Service shuttle boats leave the launch site at Lower Matecumbe Key near Mile Marker (MM) 78 daily except Tuesdays and Wednesdays. Tickets are $6 for adults, $3 for children 6 through 12. Reservations are recommended; call 305-664-4815.

LONG KEY: Camping information is available from the Long Key State Recreation Area, Box 776, Long Key, Fla. 33001, 305-664-4815. Admission for out-of-state residents is $2.50 per vehicle driver plus $1.50 per passenger. Admission for Florida residents is $1.50 and $1, respectively.

Lime Tree Bay Resort (MM 68.5, Box 839, Long Key, Fla. 33001, 305-664-4740) rates are $75 to $95 (double) during the winter, $50 to $75 during the off-season.

LITTLE TORCH KEY: At Little Palm Island (Route 4, Box 1036, Little Torch Key, Fla. 33042, 305-872-2524), accommodations for two, including three meals daily, range from $573 in the winter season (Dec. 21 to April 30) to $410 in the off-season (July 16 to Oct. 15), including gratuities. Rooms without meals run from $288 to $489, double.

RECOMMENDED READING: Joy Williams's guidebook, "The Florida Keys From Key Largo to Key West: A History & Guide" (Random House, $9.95), provides a wonderfully eccentric narrative as well as detailed service information.

INFORMATION: For more information on the Florida Keys, contact the Florida Keys Visitors Bureau, P.O. Box 866, Key West, Fla. 33041, 800-FLA-KEYS (800-352-5397). For a vacation guide to Florida, contact the Florida Division of Tourism, 126 Van Buren St., Tallahassee, Fla. 32399-2000, (904) 487-1462. -- Bill Belleville