CUMBERLAND ISLAND, Ga. — Drops of moisture fall from the Spanish moss that hangs from live oaks onto the fan-shaped palmetto fronds below. A hungry armadillo busily scavenges under vines and ferns. A breeze off the teal Atlantic plays with the mane of a sturdy feral horse trotting on the ivory sand dunes.

To land on Cumberland Island, a national seashore off the Georgia coast, is to immerse oneself in the sounds of silence just a few miles east of one of the nation's busiest interstate highways, I-95.

The southernmost of Georgia's barrier islands, it is accessible only via ferry — frequently escorted by dolphins and pelicans — and the private launch of the island's only deluxe inn. The combination of pristine nature and the high life that has marked this cluster of isles for more than a century faces new challenges this year from development plans.

Cumberland and the four barrier islands just north of it, called the Golden Isles, are separated from the mainland by a few hundred yards of golden marsh, about halfway between Savannah, Ga., and Jacksonville, Fla.

Sea Island and Little St. Simons Island are luxury getaways. The first has mansions and The Cloister, a newly renovated, exclusive resort. Little St. Simons is entirely taken up by a resort that accommodates only 30 guests.

St. Simons Island, which sits just south of Little St. Simons, has its own venerable live oaks and colonial history dating back to 16th-century Spanish explorers and 18th-century English soldiers. But with more than 15,000 year-round residents, a cluster of shops and restaurants, a pier, and an 1872 brick lighthouse, it looks more like a seaside village than do the other barrier islands.

Just south of St. Simons, on Jekyll and Cumberland islands, are the remnants of Gilded Age exclusivity and expanses of pristine wilderness. Both islands are also at the center of development debates that pit accessibility and modernization against untrammeled nature.

From 1886 to 1942, the 7.5 miles of maritime forests, dunes and sandy beaches of Jekyll Island were the winter retreat of America's elite. The Rockefellers, Vanderbilts, Pulitzers and their friends built Mediterranean-style villas — some with white and pink stucco flourishes, gold plumbing, and walls made of tabby, a man-made stone made partly from oyster shells — on the marsh-facing coast.

Anchoring their development was the turreted Jekyll Island Club, gathering spot of the men who then held between them one-sixth of the world's wealth. The historic compound, abandoned after German U-boats were spotted nearby in 1942, now welcomes visitors to a hotel and restaurants.

Beyond the remnants of the millionaires' enclave, a few oceanside, low-rise hotels disappearing into the scrubby dunes and the soft gray expanses of undeveloped beach.

UPDATING HOTELS

The entire island is property of the state of Georgia. The Jekyll Island Authority, which leases the island from the state, is required to maintain 65 percent of the land undeveloped. But the authority wants to modernize the hotels, which last saw major additions in the 1970s, said spokesman Eric Garvey.

"Our intentions on revitalization can be done well within 35 percent," he said, adding that the plan would create a "town center" with hotels, restaurants and shops where the access road to the island runs into the beachside boulevard. A lackluster convention center now stands there.

No ground will be broken until mid-2008. Any new development will have to come within the guidelines — no higher than the Club's tower, at least 50 percent landscape, barely visible above the tree lines, and nothing that would create the kind of traffic that needs a light, Garvey said.

Environmentalists and some residents who support hotel renovations remain wary of any new development that would take away the island's homey feeling, accessibility and natural areas.

"Let's see how (the old hotels) do before we build anything else," said Patty McIntosh of the Georgia Conservancy.

CHANGE IS IN THE AIR

The larger Cumberland Island, designated a national seashore in the 1970s, has no development at all, aside from a smattering of structures for National Park Service staff, campgrounds and a few of the late 19th-century mansions built by Thomas Carnegie, brother and partner of steel magnate Andrew Carnegie.

Only 300 visitors are allowed daily. It takes just seconds to lose the crowd among the moss-draped oaks that surround visitors not far from the ferry landing. But environmentalists are worried that might change. The park service is developing a federally mandated plan that would provide motorized transportation around the island, perhaps even on the beach.

"Unless you can hike, you can't see the island. That was the impetus for the plan," said Jerre Brumbelow, the island's superintendent.

The plan, which could take many shapes, will take years to implement.