Clive Runnells Family Mad Island Marsh

More than 75 years ago, an expansive coastal prairie and wetland system stretched nearly unbroken across nine million acres in Texas and Louisiana. After decades of overuse and development, only 2% endures today. This makes Mad Island Marsh Preserve an important piece of a broad network of coastal conservation lands along the Gulf Coast. Its continuum of habitat helps reduce erosion and contributes to the overall health of Matagorda Bay, which meets with the Gulf of Mexico, improving resilience for marine life, endemic plants, wildlife and coastal communities.

Situated at the confluence of two principal North American migratory bird routes, the preserve also provides nesting, feeding, resting and roosting habitat for more than 250 species of birds. Notable species include the endangered whooping crane, the rare Le Conte’s sparrow and more than 20 species of waterfowl. For years, the Smithsonian Migratory Bird Center has operated a bird banding station on the preserve to study the patterns and behavior of migratory birds. Additionally, the annual Matagorda County-Mad Island Marsh Christmas Bird Count is one of the most prominent Audubon Christmas bird counts throughout the country, ranking first in number of species tallied for more than a decade. Other wildlife species found on the preserve include everything from red drum, blue crabs, brown shrimp, southern flounder and speckled trout to bobcats, rattlesnakes, white-tailed deer and coyotes. 

The establishment of the Clive Runnells Family Mad Island Marsh Preserve dates back to 1989, when Clive Runnells II donated more than 3,000 acres of coastal wetlands and upland prairies to TNC. The land is directly adjacent to Texas Parks and Wildlife Department’s Mad Island Wildlife Management Area, which TNC helped establish with a 5,700-acre donation. In 1993, TNC added 3,900 acres to the preserve.

In the 1980s and 1990s, much of our work at Mad Island centered on enhancing the freshwater wetlands and coastal marshes for wintering waterfowl. In close partnership with organizations like Ducks Unlimited and the U.S. Fish and Wildlife Service, we created more than 500 acres of seasonally flooded wetlands that can provide critical stopover and wintering grounds for migrating birds.

Today, we’ve broadened that focus, managing the preserve using prescribed fire, invasive species control, and native seed harvesting and development—with an eye toward supporting this ecosystem’s natural processes to create functioning, connected and resilient communities that support the health of the broader Gulf Coast prairies and marsh ecoregion.