The preserve is the largest tract of undisturbed marshland left on San Francisco Bay. It takes in the Duck Pond, the Lucy Evans Baylands Nature Interpretive Center, Byxbee Park, the Harriet Mundy Marsh and the flood basin, next to the airport and golf course.
It owes much to campaigners such as Lucy Evans, “Baylands Lucy”, and Harriet Mundy, whose petition stopped a plan to develop the marsh. Ridgway’s rails and salt marsh harvest mice live there.