Time stands still on gulf's barrier islands

Coming in from the open Gulf of Mexico, miles before you can even begin to see land, Petit Bois Island, Miss., gives itself away.

There on the horizon, bright and white against a naked blue sky, a plume of light reaches toward the heavens.

The plume is centered over the island and testifies to the power of the subtropical sun, which bounces so fiercely off the miles of white sand that it actually casts a sort of reverse shadow -- this one made of light -- hundreds of feet into the sky.

Each island in the Gulf Islands National Seashore chain casts such a light.

The plume fades as you approach the island, whose eastern edge rises up from the surf as little more than a sand spit, but 2 inches above sea level and barren save for a lone black-legged stilt prospecting in the shallows. In those shallows, dozens of hermit crabs clutch and crawl across one another, stingrays slide by and glittering schools of translucent minnows flash in water less than ankle deep.

Welcome to the barrier islands of Alabama and Mississippi.

Seagrasses dot the islands

Scientists say the islands are shrinking, mostly the result of ship channels dredged in the past century. But efforts are underway to save the natural treasures.

Petit Bois (pronounced "petty boy" in the local vernacular) quickly expands from its skinny leading edge, with a broad sand flat giving way to low dunes. Step off the boat -- the only way to get to the barrier islands -- and chances are good you are the only human being on the isle.

People, beginning with the nation's earliest American Indian tribes, have likely camped on Petit Bois, just over the Alabama line, and its neighbors, Dauphin, Horn, Ship and Cat, for 10,000 years. It's easy to imagine that little has changed.

Wander inland and white morning glories stretch across the sand as far as you can see, their green vines rambling across dunes capped with yellow pencil flower peas. Toward the center of the island, the dunes flatten out and low grasses take hold. A lake is ringed with marsh grasses, cattails and sea ox-eyes. The lake holds water more fresh than salt, a welcome oasis to thousands of migratory birds looking for a first drink after flying across the gulf from South America.

Some islands accessible by car

Horn Island still has its forest, thanks to higher sand dunes.

On both islands, dwarf live oaks, slash pines and even magnolias still stand tall, home to a unique group of plants and animals, ranging from one-lined tree frogs to rattlesnakes.

Although it's considered a jewel of the National Park Service, the Gulf Islands National Seashore remains a lightly used paradise.

Perdido Key and Santa Rosa Island in Florida can be reached by car and offer spectacular views and that rarest commodity in Florida -- beaches unmolested by towering condominiums or mini-golf courses. In Mississippi, the Davis Bayou area can be reached by car, while a daily ferry runs to Ship Island from Gulfport.

If you have a boat, then the Gulf Islands National Seashore is truly your oyster, offering a chance to visit a dozen beaches in a day. But bring enough gas to get your craft home, as none of the islands has a marina. Getting to the islands should be attempted only by experienced boaters comfortable in heavy seas.