Hydrologic Units (HUC4) California Department of Fish and Wildlife Code Name 1503 Lower Colorado SWAP 2015 Study Regions 1604 Black Rock Desert - Humboldt 1605 Central Lahontan Oregon - Oregon Closed 1606 Central Nevada Desert Basins Washington Coastal Basins 1710 Oregon - Washington Coastal HUC1710 HUC1712 1712 Oregon Closed Basins 1801 Klamath - Northern California Coastal 1802 Sacramento 1803 Tulare - Buena Vista Lakes M261A M261D 1804 San Joaquin M261G 1805 San Francisco Bay Klamath - Northern Black Rock 1806 Central California Coastal California Coastal Cascades Desert - Humboldt 1807 Southern California Coastal HUC1801 and Modoc HUC1604 1808 North Lahontan North 1809 Northern Mojave - Mono Lake PlateauLahontan HUC1808 1810 Southern Mojave - Salton Sea 342B North M261C California Ecoregions Coast and Code Name North 341D 261A Central California Coast Coast Klamath M261B 261B Southern California Coast Marine Sacramento Deserts HUC1802 262A Great Valley Conservation 263A Northern California Coast Unit 322A Mojave Desert 322B Sonoran Desert 322C Colorado Desert Central 341D Mono Lahontan Central HUC1605 341F Southeastern Great Basin 342B Northwestern Basin and Range 263A Valley and Central Nevada M261A Klamath Mountains North Central Coast Desert Basins M261B Northern California Coast Ranges Marine Conservation Sierra Nevada HUC1606 Unit M261C Northern California Interior Coast Ranges M261F M261E M261D Southern Cascades San Joaquin 341D M261E Sierra Nevada HUC1804 San M261F Sierra Nevada Foothills Francisco Bay 261A M261G Modoc Plateau HUC1805 M262A Central California Coast Ranges Bay 262A Delta M262B Southern California Mountain and Valley 341F and 341F Central Marine Coast Northern Mojave M262A Tulare - Buena - Mono Lake Central HUC1809 Vista Lakes Central Nevada California Coastal HUC1803 HUC1806 Desert Basins Central Coast 322A HUC1606 Marine Conservation Unit Deserts Lower Southern Colorado California Coastal HUC1503 DRAFT HUC1807 Southern Mojave 261B South - Salton Sea HUC1810 322B 261B Coast (Channel Legend Islands) M262B Study Regions 322C San Francisco Bay-Delta unit (with 1m sea-level rise adjustment) Marine Conservation Units North Coast South Coast North Central Coast Marine Conservation Central Coast Unit South Coast California Ecoregions California Department of Fish and Wildlife Habitat Conservation Planning Branch. D.Mastalir. 20140602 Data Sources: HUC from National Hydrography Dataset. Ecoregions from USDA Forest Service. Marine Conservation Untis and SF Bay unit from California Department of Fish and Wildlife.Hillshade Background: ESRI (copyright 2013).