More than a thousand miles from any coast, the marshes are one of the only places in the United States where the naturally occurring water is saline. In addition to providing the flood protection wetlands are known for, they’re a refuge for species uniquely adapted to salty conditions.

But a hundred years of building roads, homes, stores, and offices in and around Lincoln, a city of more than 280,000, have filled in and carved up roughly 80 percent of the marshes. It’s estimated that nearly 20,000 acres of salt marsh once existed; today only 4,000 acres remain scattered throughout the region.

Of more than a million acres of wetland that dot Nebraska, the salt marshes around Lincoln are the most endangered. If these salt marshes disappear, so too will Nebraska’s reminder that their prairies were once dominated by the shallow seas of the Western Interior Seaway.