Quimby Island is a small island in the

Sacramento–San Joaquin River Delta The Sacramento–San Joaquin River Delta, or California Delta, is an expansive inland river delta and estuary in Central California and Northern California Northern California (commonly shortened to NorCal) is a geocultural region that ...

, whose coordinates are . It is in

Contra Costa County Contra Costa County (; ''Contra Costa'', Spanish language, Spanish for 'Opposite Coast') is a U.S. county, county located in the U.S. state of California, in the East Bay of the San Francisco Bay Area. As of the 2020 United States census, the ...

, and managed by Reclamation District 2090.

References

Islands of Contra Costa County, California Islands of the Sacramento–San Joaquin River Delta Islands of Northern California {{ContraCostaCountyCA-geo-stub