Wednesday, September 9, 2020

Mono Lake South Tufa

Tufa towers rise by the shore of Mono Lake
1 mile loop, 50 feet elevation gain
Difficulty: Easy
Access: Good gravel road to trailhead, National Forest fee required

The enchanting, tranquil waters of California's Mono Lake are tucked into a desert basin east of the high Sierra Nevada. The shores of this otherworldly lake are dotted with bizarre, contorted rock pillars known as tufa: the South Tufa area on the south shore of the lake is the best place to visit the lakeshore and see these calcium carbonate oddities. Mono Lake is an ecologically fascinating place with a harsh beauty, a keystone to many California ecosystems. I highly recommend that any American make a visit to this lake, especially if you're visiting nearby Yosemite National Park, as the rich ecological and historical complexities of this place make it a profoundly moving landscape. This hike visits some of the best scenery around Mono Lake in just one short mile of hiking amongst tufa towers.

Mono Lake is a long way from any major metropolitan area; Modesto and Reno might be the closest larger cities. The closest services to the South Tufa area are in the small town of Lee Vining, above the lake's western shore. From Lee Vining, I followed US Highway 395 south five miles and then turned left onto CA Highway 120, following it east for another five miles to the turnoff for Navy Beach and the South Tufa area. The paved road ended at a split between the roads to South Tufa and Navy Beach; I took the left fork, which led to the South Tufa parking area via a good gravel road. There was a large parking area at the end of the road; a $3 fee per person is necessary to park here, although if you have an America the Beautiful Pass or another federal lands recreation pass, that's valid for parking here as well. There's a row of vault toilets at the trailhead.

A quick note: at the time of publication, the South Tufa Area at Mono Lake had closed due to the Beach Fire, a lightning-sparked wildfire that started just two days after I visited. Damage to the tufa and the trail did not seem to be extensive, but it's likely that the South Tufa Area will be closed for the rest of 2020.

From the trailhead, a paved path led north on a barely noticeable downhill grade towards the lakeshore. Coming before sunrise, I was able to appreciate the intense color that the predawn sun painted on the clouds to the east as I walked through the sagebrush desert towards the lakeshore.

Sunrise over the Mono Basin
As I followed the paved trail towards the current lakeshore, I walked on land that only decades ago was part of Mono Lake's lakebed. Mono Lake is an endorheic lake occupying one of the many basins of the Great Basin, meaning that it is a lake that does not drain to the sea. This lack of an outlet concentrates salts and minerals that flow down from streams draining the nearby Sierra Nevada- in fact, Mono Lake is over twice as salty as the ocean. The lake is one of two claiming to be the 'Dead Sea of California' (the other is the Salton Sea in the southern part of the state) due to its high salinity and desert setting. Many lakes once filled the depressions of the Great Basin, including the massive Lake Bonneville that once covered much of the eastern Great Basin in Utah; an increasingly arid climate and decreased snowpack has dried out most of the basins, so today most of the lakes left in the Great Basin abut either the Sierra Nevada in California or the Wasatch Range in Utah, which deliver enough snowmelt into these basins to offset evaporative losses from these desert lakes.

At the turn of the twentieth century, Los Angeles was a quickly growing city in southern California, but the arid conditions of the Los Angeles Basin made a city with a large population there unsustainable. City leaders, along with engineer William Mulholland, who led an agency that is today the Los Angeles Department of Water and Power (LADWP), looked to the Eastern Sierra for a solution. Under Mulholland's direction, the city of Los Angeles bought up land in the mountains above Owens Valley, diverting snowmelt into a newly constructed Los Angeles Aqueduct that carried water hundreds of miles from these mountains to the lawns and citrus groves of the newly booming metropolis. Owens Valley, which was once watered by the melting snows of the Sierra, became an arid wasteland. By the 1930s, Los Angeles was still growing and voracious for more water. The LADWP bought up land in the Sierra above Mono Lake and extended the Aqueduct. Starting in 1941, the agency began to divert most of the streams flowing into the Mono Basin. The lake level began to drop almost immediately.

Dropping lake levels had many effects; one was to expose the tufa formations that were once below the lake. These fragile rock pillars are made when underwater springs high in calcium feed into Mono Lake's carbonate-rich waters. Calcium carbonate pillars then form underwater around the springs. Mono Lake was once much larger during previous ice ages and more tufa towers can be found on dry land around the Mono Basin; but the retreat of the lakeshore following LADWP water diversions exposed a large collection of tufa towers that had been underwater prior to 1941.

Arriving at the lakeshore, I found the most extensive collection of tufa at Mono Lake. Some tufa were now fully on dry land, surrounded by sage that had grown in the intervening time since the beginning of the LADWP water diversions. Other tufa formations were on the lakeshore or in the lake itself. Each was a contorted, bumpy pillar of grey and white rock, the chimneys and towers of a silent rock city. The Sierra Nevada rose to the west of the lake, making a dramatic backdrop to the tufa formations here; Mount Dana and Mount Gibbs were particularly impressive, rough ridges towering over the far gentler terrain of the Mono Basin.

Tufa towers and the Sierra Nevada rise over Mono Lake
The ethereal mood of Mono Lake's waters is in part due to the lake's odd chemistry: this extremely alkaline lake has been noted to have a soapy feel. The high pH (around pH 10 at current lake levels) makes the lake inhospitable for fish, but the lake does support an enormous population of endemic brine shrimp. Look into the waters of the lake in summer and you may see dense concentrations of these shrimp: during warm months, the population of brine shrimp in the lake likely enters the trillions. These brine shrimp attract California gulls to the lake. Eighty percent of the state's gulls come to Mono Lake during the summer to nest on Negit, one of the two volcanic islands in the heart of the lake. The island's isolation from mainland predators make it an ideal place to nest, with the lake's brine shrimp providing a bountiful and reliable food source during nesting. Before they crowd the beaches of Santa Monica and San Francisco's Fisherman Wharf, most seagulls in California are born to the serene desert landscape of Mono Lake. The gulls are not Mono Lake's only avian visitors: migratory birds such as avocets and phalaropes come from across the continent to feed here seasonally.

Mono Lake South Tufa
The declining lake levels due to LADWP's water diversions began to threaten these nesting birds in the late twentieth century: as the lake levels dropped more than 42 feet in elevation, a land bridge formed between Negit and the mainland, bringing coyotes and other predators to the gulls' nesting grounds. In the 1970s, environmentalist David Gaines was alarmed by the effects of the water diversions on the lake's unique ecosystem; in 1978, he cofounded the Mono Lake Committee. Scientific research at the time found that the water diversions had halved the lake's volume since 1941 and were endangering a critically important ecosystem. Using these conclusions, Gaines and the Mono Lake Committee sued the LADWP in a series of cases that led to a 1994 ruling that required the LADWP to release enough water into Mono Lake to maintain its water level 17 feet above the low water level at the time of the ruling. A major victory for environmentalists and the lake's ecosystem, water releases have since brought the lake level up 7 feet from its low point in the 1990s.

Tufa in the lake
After the paved trail ended at the lakeshore, I followed a dirt path east across a small peninsula packed with tufa formations, enjoying views of the lake in all directions. Looking east, I saw the sun rising above a long stretch of beach on the lakeshore. This is Navy Beach: in the 1950s, the US Navy built a secret weapons testing facility here on the south shore of Mono Lake, establishing a small base here. The facility was short-lived, decommissioned and deconstructed in 1962.

From here, I followed a flat and slightly brushy trail back towards the parking lot through the sagebrush, passing by many more tufa formations before I arrived back at the trailhead.

Tufa towers
Mono Lake is an extraordinary landscape, an ethereal desert Dead Sea that supports abundant life and epitomizes the tension between nature and human demand for water in California. This short and easy hike can allow you to reflect on the remarkable natural and human history of this place while enjoying the most extensive and scenic collection of tufa at the lake.

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