10 feet of rain came down over 43 days in California and surrounding areas then in 1862 floods

The event dumped an equivalent of 10 feet (3.0 m) of precipitation in California, in the form of rain and snow, over a period of 43 days.^[3][4] Immense snowfalls in the mountains of far western North America caused more flooding in Idaho, Arizona, New Mexico, as well as in Baja California and Sonora, Mexico the following spring and summer, as the snow melted. 

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Great Flood of 1862