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. 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 event dumped an equivalent of 10 feet of rainfall in California, in the form of rain and snow, over a period of 43 days. Immense snowfalls in the mountains of the far western United States caused more flooding in Idaho, Arizona, New Mexico, and Sonora, Mexico the following spring and summer as the snow melted.