The Suisun Marsh is the largest brackish water marsh on west coast of the US, and is home to more than 220 bird species, 45 mammal species, 16 different reptilian and amphibian species, and more than 40 fish species. The Marsh also supports sensitive plant species like the Suisun thistle, which is found nowhere else in the world.
The sign here has some plaques with great information about the marsh (which you should ta a moment to read), and how special of an area it is,