MEXICO BEACH

Marilyn Theus peddles costume jewelry, chipped China plates and other "junktiques" on the roadside between Port St. Joe and Mexico Beach. On Tuesdays she's joined by a friend who markets fresh shrimp from the site overlooking the turquoise waters of St. Josephs Bay.

The vendors are part of the local charm of Florida's Forgotten Coast, which stretches along the Gulf of Mexico from Mexico Beach to about 100 miles east to St. Marks. Mom and pop motels, bait shops and undeveloped beaches dot the coast south of the Apalachicola National Forest.

But a new $330 million international airport, pushed by The St. Joe Co. and political leaders over the objection of environmentalists, is scheduled to open in early 2010 on a 4,000-acre site north of Panama City. It could mean big changes for these quiet oyster and shrimping towns, long bypassed by tourists.

Formed by the duPont family to harvest timber for paper products in the 1930s, The St. Joe Co. is now a developer and owns some 700,000 acres of undeveloped Florida land mostly in the Panhandle, making it the state's largest private landowner. St. Joe donated the 4,000 acres to relocate Panama City's exiting airport and owns 78,000 acres of undeveloped property surrounding the new airport.

Along The Forgotten Coast, the state — with the help of a land donation from the St. Joe Co. — recently rerouted four miles of U.S. 98, the major east-west coastal highway, to improve the traffic flow in the area and make way for development. High-end vacation homes began replacing motels and RV parks a decade ago. In sleepy Port Saint Joe, trendy interior decorating stores have opened near the local Piggly Wiggly.