2015 Map of Bouldin Island

About this map

The San Joaquin River and its intricate network of sloughs and cuts define this portion of the California Delta at the convergence of Sacramento, San Joaquin, and Contra Costa Counties. This landscape of reclaimed land is dominated by large tracts like Bouldin Island, Venice Island, and Mandeville Island, separated by deep-water arteries and narrow channels. The Stockton Deep Water Channel cuts through the river's reach, facilitating maritime transit through the heart of the valley. Settlement is concentrated at Bethel Island in the southwest, where a residential grid meets the water at Piper Slough. Levee roads, including W Mandeville Levee Rd and Mandeville Levee Rd, trace the perimeter of these low-lying islands, highlighting the precarious balance between the fertile valley floor and the surrounding waterways of the South Mokelumne River.