The Great Flood of 1862
“The Great Flood of 1862 was the largest flood in the recorded history of Oregon, Nevada, and California, occurring from December 1861 to January 1862, caused by an ARkStorm.
It was preceded by weeks of continuous rains and snows in the very high elevations that began in Oregon in November 1861 and continued into January 1862.
This was followed by a record amount of rain from January 9–12, and contributed to a flood that extended from the Columbia River southward in western Oregon, and through California to San Diego, and extended as far inland as Idaho in the Washington Territory, Nevada and Utah in the Utah Territory, and Arizona in the western New Mexico Territory.
The ARkStorm dumped an equivalent of 10 feet of rainfall in California, in the form of rain and snow, over a period of 43 days....
...It has been described as the worst disaster ever to strike California...
... In 2012, hydrologists and meteorologists concluded that the precipitation was likely caused by a series of atmospheric rivers that hit the Western United States along the entire West Coast, from Oregon to Southern California...
https://en.wikipedia.org/wiki/Great_Flood_of_1862
I recall reading scientists discovered, in the sediment records, that this sort of flood repeatedly happened in California, with about 150 years between occurrences.
In other words, we are about due for another one.
The central valleys were under water.
Interesting info.