Sutter Buttes or Sutter Sea?

During the 1860s the capital of California was moved from Sacramento to San Francisco and other cities as the SEA as you say became the only means of travel. Those heading to Oroville took a heading on the Sutter Buttes as they were the only notable landmarks protruding above the vast sea of water. From Oroville navigate North-East. For Newville; head for the North-West from the Sutter Buttes.

This was a two-year-plus rain event that included the Europeans.

— Chuck Jasper, Corning