The Antioch Dunes National Wildlife Refuge along the San Joaquin River is undergoing a transformation.
The Port of Stockton must dredge its Deep Water Channel regularly so that ocean going vessels can sail through it. The sand used to go toward building up Delta levees, but now the sand is rebuilding the Antioch Dunes National Wildlife Refuge.
After the 1906 San Francisco earthquake, sand from the dunes was used to make bricks to rebuild the city and the 100-200 foot dunes shrank to ground level.
Port Director Richard Aschieris says the port is working with the U.S. Fish and Wildlife Service to restore the dunes and the habitat for the Lange's Metalmark Butterfly, a species that is only found here.
"At one time there were thousands of them. Now the counts can vary, but the last I heard, there's less than 200 of what's called the Lange's Metalmark butterfly are left."
Aschieris says it could take a decade to restore the dunes to their original state. But as the work progresses, native plants and the butterfly should begin to flourish.