The low ridge at the south end of This valley forms the south
rim of the Great Basin, which in prehistoric times was the bed of a
vast body of water now referred to as Lake Bonneville.
Lake Bonneville extended 350 miles to the north and was in
places 145 miles wide with a maximum depth of 1050 ft. Lake
Bonneville was a prehistoric pluvial lake that covered much of
North America's Great Basin region. Most of the territory it
covered was in present-day Utah, though parts of the lake extended
into present-day Idaho and Nevada. Formed about 32,000 years ago,
it existed until about 16,800 years ago, when most of the contents
of the lake were released through the Red Rock Pass in Idaho. Many
of the unique geological characteristics of the Great Basin are due
to the effects of the lake.
Like most, if not all, of the ice age pluvial lakes of the
American West, Lake Bonneville was a result of the combination of
lower temperatures, decreased evaporation, and higher precipitation
that then prevailed in the region, perhaps due to a more southerly
jet stream than today's. The lake was probably not a singular
entity either; geologic evidence suggests that it may have
evaporated and reformed as many as 28 times in the last 3 million
years.
To log this cache as "Found," e-mail us the answers to the
following questions and include a photo in your online log of you
at the cache site with your GPS:
Email us and tell us :
- the name of the first scientific explorer of Lake Bonneville
and when he explored it.
- what happened to the lowest parts of the lake and why.
- When you get home please read up on The Great Basin and Lake
Bonneville, there is A LOT of information out there, and put
something interesting learned about them in your online log.
