A gigantic map of all the cool plaques in the world. A project of 99% Invisible. Logo by Chop Shop

Avery Island Salt Dome

Avery Island stands out from the surrounding wetlands, rising at its highest point 163 feet above the low-lying plain. This salt dome formed as the weight of younger sediment pushed up a column of salt deposited over 165 million years ago. Like other salt domes in the “Five Island Trend”—which also includes Jefferson Island, Weeks Island, Côte Blanche Island, and Belle Isle), Avery Island’s salt formation approaches close enough to the surface to create a topographic rise. This is known locally as an “island” because of its height relative to the neighboring land and insular appearance from a distance.

The Island is surrounded by a salt marsh, a cypress swamp, and bayous (small, slow-moving muddy rivers), including Bayou Petite Anse. Petite Anse means “Little Cove” in Louisiana French, and the Island itself was known as Île Petite Anse from the early to mid-nineteenth century. Its rich natural resources encouraged settlement, first by prehistoric Native Americans, then in the late eighteenth century by European pioneers.

Vegetation on the Island includes live oaks, magnolias, pecans, camellias, irises, bamboo, and wisteria, among other varieties. Wildlife includes alligators, deer, bobcats, coyotes, snakes, turtles, and many bird species.

Salt extraction has occurred on Avery Island since prehistoric times, when Native Americans boiled briny spring water to collect salt. Using this same method, American settlers in the early nineteenth century extracted salt on the Island. After the Civil War, rock salt was first mined using shafts, tunnels, and galleries. Today the salt mine extends down about 2,000 feet.

Oil production also occurs on the Island. Petroleum was first discovered here in commercially viable amounts in 1942. It continues to be extracted today—always with extreme care for the local environment.

In the mid-1860s Edmund McIlhenny began growing Capsicum frutescens peppers here using seeds believed to be from Mexico or Central America. Around 1868 he created the first bottles of his now world-famous TABASCO® brand Pepper Sauce. Edmund’s son, Edward Avery “Ned” McIlhenny, grew up on the Island and studied its plants and animals. In 1895 he founded the private Bird City sanctuary to re-establish the population of snowy egrets—a species that had nearly become extinct because its feathers were prized by hat makers. Around that time Ned also developed a semi-tropical garden on the Island. He opened it to the public in 1935 as Jungle Gardens, a botanical wonder covering about 170 acres. It includes the rookery, a seasonal home for thousands of egrets (from February through August) and other migratory birds.

Nearby Plaques On Google Maps