RACHEL MARTIN, HOST:
In California, state officials are planning a multibillion-dollar environmental restoration of the inland delta near San Francisco Bay. There's one problem though: no one knows what the landscape used to look like since 97 percent of the original wetlands are gone. So, now the state is looking for help from historians. Lauren Sommer from member station KQED has the story.
LAUREN SOMMER, BYLINE: This detective story begins on a sunny day in a dry field of corn about an hour east of San Francisco.
ALISON WHIPPLE: I mean, he was probably, once he got lost, they were wandering all over the place.
ROBIN GROSSINGER: They were all over this place, huh.
SOMMER: Alison Whipple and Robin Grossinger are looking through a pile of maps, trying to piece together the path of William Wright, a man who got hopelessly lost somewhere nearby.
WHIPPLE: So, he's coming from right over there on our left.
SOMMER: I should probably mention - this happened 160 years ago. Whipple and Grossinger are historians - or historical ecologists, to be more precise - with the San Francisco Estuary Institute. They dig up old photos and hand-drawn maps that provide clues about what this landscape once looked like. In this case, they're relying on a tattered, yellowing notebook.
WHIPPLE: Two stories, actually, written by a guy who was a duck hunter around 1850.
SOMMER: Here's what William Wright wrote about a long, cold night lost in a damp marsh:
UNIDENTIFIED MAN: (Reading) On all sides stretched a vast wilderness of tules from ten to fifteen feet in height. The driving storm of sleet was bad, but the pitchy darkness was infinitely worse.
SOMMER: When Whipple and Grossinger read this, they knew they'd stuck gold. Not because of the dramatic story.
UNIDENTIFIED MAN: (Reading) Our situation was so miserable that no words can do justice to it.
SOMMER: But because of passages like this:
UNIDENTIFIED MAN: (Reading) The lakes proved to be from one hundred to three hundred yards in width, as near as we could judge.
SOMMER: These details, says Grossinger, reveal a landscape hasn't existed for some time.
GROSSINGER: The Delta is probably one of the most intensively transformed parts of California and it was also changed really early on because of such fertile land.
SOMMER: As the Gold Rush boomed, farmers came to California's Delta for the rich soil. Land went for a dollar an acre and settlers drained the wetlands, turning it into dry farmland. That meant the loss of fish and other wildlife.
GROSSINGER: We have here maybe one of the most important parts of the state's ecosystem and we don't actually know how it used to work.
SOMMER: That's why they've stitched together thousands of historical documents that reveal lost lakes and floodplains. There were once hundreds of miles of tidal channels that branched out like capillaries. Returning the Delta to this pristine state just isn't possible, says Grossinger, and that's not the goal of the project. But knowing how the ecosystem once worked could improve the habitat restoration that will happen.
CARL WILCOX: So, this is south, this is north, this is Liberty Island.
SOMMER: Carl Wilcox is with California's Department of Fish and Game. The island he's showing me is really more of marsh now.
WILCOX: The levees broke and it wasn't financially worth reclaiming.
SOMMER: Liberty Island was like the other man-made islands here - a plot of low-lying farmland, protected by tall levees. After the island flooded 15 years ago, nature took over. Tules and cattails started sprouting.
WILCOX: Some of the endangered native fishes, Delta smelt, longfin smelt are using this area.
SOMMER: So are endangered Chinook salmon.
WILCOX: These are more productive areas for them. They're more protected, they're less prone to predators.
SOMMER: This restoration was accidental, but Wilcox says the state wants to restore more than 100,000 acres of habitat like it. It's part of a plan to build massive water tunnels nearby, which would supply two-thirds of the state with drinking water. Wilcox says that project won't move ahead unless endangered species start recovering. And that depends on recreating habitat that was here more than 150 years ago. For NPR News, I'm Lauren Sommer in San Francisco.