Port Fourchon feels like the edge of the world. As you drive south on Louisiana Highway 1 through Bayou Lafourche, open marshes seem to stretch endlessly until you reach this spot, 60 miles below New Orleans. There, the marsh once known as trembling prairie meets the Gulf of Mexico. This is an oil-services installation. And though its existence is unknown to most Americans, it is vital to them. Without Port Fourchon and its fleet of vessels bringing food, supplies, equipment, and reinforcements to platforms in the gulf, the U.S. would lose access to nearly a fifth of all the oil and gas it uses. Port Fourchon is also home to pipelines, miles and miles of them. There are the feeders from the Louisiana Offshore Oil Port, which accommodates the massive tankers that deliver 11 percent of the nation's foreign oil.