Geoscience Reference
In-Depth Information
CA
1861-62
Flood Areas
Sacramento
San
Francisco
Mojave
Desert
Los
Angeles
San
Diego
f igu r e 9. Map of California showing the approximate areas of l ood-
ing in 1861-62. h e white regions on the map show the lowest elevations
in the state, most of which were under water during the l ood. (Map
redrawn by B. Lynn Ingram.)
h
e Central Valley Submerged
In the Sierra Nevada, cold arctic storms dumped ten to i t een feet of snow
that winter, and these were soon followed by atmospheric river storms,
which, as will be discussed later in this chapter, poured heavy warm rains
on the snow. Unable to penetrate the still-frozen soils, an enormous pulse of
water from the rain and melted snow l owed downslope and across the land-
scape, overwhelming streams and rivers and creating a huge inland sea in
California's enormous Central Valley—a region at least 400 miles long and
up to 70 miles wide (see i gure 9). h is vast, temporary inland sea covered
farmlands and towns, drowning people, horses, and cattle, and washing
away houses, buildings, barns, fences, and bridges. On January 18, 1862, the
following appeared in the
Contra Costa Gazette:
