Suisun Marsh is a 470 km2 wetland situated between the Sacramento-San Joaquin Delta and San Pablo Bay in the San Francisco Estuary. Today, about 80 percent of the marsh plain is privately owned by duck hunting clubs and managed in accordance with conservation agreements. A complex network of sloughs weaves through the Marsh, providing habitat for numerous aquatic species. Together the waterways and marsh plain support a stunning array of species, provide exurban open space, and are increasingly called upon to meet regional conservation objectives. The Marsh is vulnerable to sea level rise impacts, pollution, and other human impacts, so understanding how it functions so it can be successfully managed to meet the lofty objectives set out for it will be critically important in the decades ahead. This study reviews landscape-scale historical ecology of Suisun Marsh and examines recent variation in fish populations from a geographical perspective. Chapter 1 presents the geomorphic and physical history of the landscape, explaining processes driving wetland development and contributing to unique functional subregions within the Marsh. Chapter 2 examines human- and animal-landscape interactions. Ecologically significant shifts in human and animal populations during the Spanish and Mexican eras, followed by agricultural development in the late 1800s and duck club management starting around 1900, have kept the Marsh landscape continually changing. The rate and magnitude of landscape change has intensified since European contact in 1769 and even more since the Gold Rush of 1849. Chapter 3 explores landscape-scale variation in species distribution and abundance based on a long-term study of Suisun Marsh fishes and invertebrates and presents these data in novel animations. Animated maps are used to explore shifting populations of fishes and invertebrates from 1980 to 2013, demonstrating the value of long-term biogeographical datasets in understanding biological communities at the landscape scale. Understanding both the deep and recent history of the Marsh provides insights and inspiration, informs management approaches, points to potential restoration and rehabilitation targets, and affects attitudes about appropriate human interactions with this dynamic biological system and landscape.