Friday, October 6, 2017

Twain Harte Lake - Tuolumne County, California


Visited on 10/2/2017 on my way up Highway 108 to give an examination for work over at Owens Valley Conservation Camp.  This Lake is located northeast of Sonora, CA in the small community of Twain Harte, California.  This cute little lake is actually a reservoir created by Twain Harte Dam and it is a multiple arch dam.  Developers began building Twain Harte Dam in the summer of 1927.  It was completed in 1928 and is a private gated lake owned by the Twain Harte Lake Association. The dam is 36 feet high, 325 feet in length, and 8 feet in width. The dam has a crest elevation of 3,510 feet and its surface acreage is only 12 acres.  In August 2014, fracturing of a granite dome known as "the Rock" located adjacent to the dam forced the closing and draining of the lake for safety reasons.  It was feared the dam would fail and there would be a flash flood in Sullivan Creek. The cause of this fracturing is a process known as exfoliation.

 

Mono Lake - Mono County, California


This picture was taken from the overlook northwest of the Lake about 10 miles on Highway 395.
 
Visited on 10/2/2017 while driving to give an examination at Owens Valley Conservation Camp.  One of the largest lakes in the State of California at 13,000 acre feet and at an elevation of 6,383 feet above sea level and looks different every time I visit it.  These pictures were taken in the late afternoon with a chill in the air. Mono Lake is a saline lake on the east side of the Sierra Nevada. It is endorheic, meaning that it does not connect with the sea. It is fed by streams flowing off the east side of the mountain range, including Rush Creek, Lee Vining Creek and Mill Creek. Lee Vining Creek has its headwaters near Tioga Pass, near Yosemite National ParkThe lake covers 69 square miles and is about 4.7 miles long. It is a very ancient lake, and is thought to have formed 760,000 years ago. In the 20th century, the city of Los Angeles began to take water from the streams feeding Mono Lake. This caused the lake to fall, exposing unique tufa formations.  The lack of an outlet causes high levels of salts to accumulate in the lake. These salts also make the lake water alkalineThis desert lake has an unusually productive ecosystem based on brine shrimp that thrive in its waters, and provides critical nesting habitat for two million annual migratory birds that feed on the shrimp and blackflies (that also feed on the shrimp). Historically, the native Kutzadika'a people derived nutrition from the Ehpydra hians pupae, which live in the shallow waters around the edge of the lake having been hatched from the eggs of adult alkali fliesWhen the city of Los Angeles diverted water from the freshwater streams flowing into the lake, it lowered the lake level, which imperiled the migratory birds.


This picture was taken from the southwest side of Mono Lake on the roadside of Highway 395.