No, the article makes it sound like Spain knew before even 1600, but used these maps as a political maneuver.
> Spanish authorities and local residents were well aware where the actual northern terminus of the Gulf of California lay, but by extending the coastline north past Cape Mendocino and eventually even into Puget Sound, Sir Francis Drake's claim of Nova Albion for England (1579) could be invalidated by the priority of Cortes' claim (1533)
> Spanish authorities and local residents were well aware where the actual northern terminus of the Gulf of California lay, but by extending the coastline north past Cape Mendocino and eventually even into Puget Sound, Sir Francis Drake's claim of Nova Albion for England (1579) could be invalidated by the priority of Cortes' claim (1533)