Scientists at the California Department of Water Resources are finding the Delta’s most elusive residents means digging deep down into the microscopic traces they leave behind.

Lake Oroville Update July, 3 2026, detailing Wildlife Safety at the State Recreation Area and free fishing day!

This annual change in regulations is driven primarily by what scientists know about the life cycles and movements of native fish species that include Delta smelt, longfin smelt, steelhead, and Chinook salmon.