US 395, Part 8: Mono County (Mono Lake to Bridgeport)

Lee Vining (population 398 [2000]) is the gateway to Mono Lake, Mono county's most recognizable geological landmark. Its otherworldly fragile tufa spires have graced photographic studies and even record albums (Pink Floyd's haunting Wish You Were Here is the most famous, featuring a shot of a diver submerged for so long that the ripples stopped; a scan from the album is at right), but the park actually has far more than the tufa: it is still a water park and it is actually legal to swim in Mono Lake, though the water is unbelievably salty; it's teeming with life, despite its apparent inhospitality; and there are numerous other unusual formations and volcanic structures, including the Panum Crater. This is a nice description of the lake's history, ecology and indigenous peoples by the Mono Lake Committee.

Modern geology believes that the Mono Basin was a consequence of three or four million years of westward tilting and sinking from the surrounding faultline and volcanic activity we have already borne witness to in Mono county. As the western floor further sank, the southern and northern borders tilted into the centre, forming a "basin" into which water could settle. It is estimated that the lake itself formed somewhere around one million years ago, and in the twilight of the last great Ice Age ca. 12,000 BC, Mono Lake even overflowed its banks to depths of 900 feet and a volume some five times greater than today. Its briny quality and soapish, alkaline waters are due to a constant evapouration process that removes fresh water from the lake, leaving behind only the salt and sediments brought into it by feeder streams. Thanks to the cumulative aeons over which this process has occurred, Mono Lake is nowadays over twice as salty and eighty times as alkaline as the ocean. As a component watershed of the Great Basin of the western United States (to be discussed more in Part 16 and on), it has no outlet to the sea.

Mono Lake was also the site of a minor gold rush when an Army patrol led by Lt. Tredwell Moore pursuing a Miwok Indian band and their leader Chief Tenaya discovered the lake -- and gold flakes nearby -- in 1852. It was Moore, in fact, who gave the lake its name having been told the name of the local tribe by his Yokut Indian guide. Mining activity would persist into the 1860s.

In 1941, Mono Lake's surface stood at 6,417' above sea level. This was the point at which the city of Los Angeles started diverting some of Mono Lake's feeder streams off as another source for the Los Angeles aqueduct system, eventually taking over four of the five to augment the city's water supply. Starved of its water sources, the lake's level precipitously dropped nearly 40 feet, revealing 17,000+ acres of "relicted" lands on which the most famous of the modern-day tufa structures stand (these southernmost tufae off CA 120 are somewhere between 200 and 900 years old, but there are other tufae surrounding the lake basin along Mono Lake's ancient Ice Age shore dating back some thirteen millenia). Eventually, sixteen years of research, court battles and legal wrangling between local preservationists and the city culminated in a 1994 compromise ruling from the State Water Resources Control Board mandating a 17-foot rise program to restore the lake to 6,392' over the following two decades. This process is, as of this writing, half complete. The compromise means not only the continued survival of a fascinating natural relic but also of its unearthly and beautiful underwater structures, now brought to terrestrial climes for generations more to see.