The lake sits near the border of California and Nevada, about fourteen miles from Yosemite National Park, east of the Sierra Nevada Mountains. It is bordered by many small towns, like Lee Vining.

The lake is well-known for its incredibly high salinity. It is, on average, 2.5 to 3 times more salty than the ocean. These salt levels have made the water alkaline, resisting acidification (also known as a soda lake). This kind of lake is characterized by its highly productive ecosystem and can be found worldwide. 

The white rocks and waters of Mono Lake on the South Shore
The white rocks and waters of Mono Lake on the South Shore


Facts About Mono Lake 

  • Average Depth: 57 ft
  • Maximum Depth: 159 ft
  • Surface Area: 45,133 acres
  • Elevation: 6,383 ft above sea level
  • Primary Outflow: Evaporation 
  • Islands: Negit and Poaha Islands 


What is Special About Mono Lake?

Mono Lake is special for the tufas (rock formations), salinity, and islands.

Mono Lake is an incredibly special place. It formed at least 760,000 years ago in an endorheic basin, or a basin that lets water in but doesn’t allow it to escape except through rivers and streams. In the case of Mono Lake, the only way water escapes is through evaporation. This means that it is a “closed lake,” the primary reason it has become as salty as it is.

Mono Lake with Sierra Nevada Mountains in the distance
Mono Lake with Sierra Nevada Mountains in the distance


Tufas

One thing that draws visitors to Mono Lake is the tufas or rock formations. These are visible to varying degrees depending on how high the water level is. Tufas are columns of limestone that took many decades or centuries to form and can be seen above the lake’s surface. The first description of these tufas dates back to the 1880s and the work of Edward S. Dana and Israel C. Russel. Below.

View of the tufas jutting out from the surface of Mono Lake
View of the tufas jutting out from the surface of Mono Lake


Salinity 

The lake is well-known for its salinity (discussed in more detail below), making the water at least 2.5 times saltier than the ocean. The salt coats the limestone rocks on the beach around the lake and covers the shore. After a short visit, one can expect to find a thick layer of salt covering the bottoms and sides of their shoes. 

The salty beach along the shore of Mono Lake.
The salty beach along the shore of Mono Lake.


Islands 

Mono Lake is home to two relatively large islands (and many smaller rock formations). These are known as Negit and Poaha Islands. They can be seen clearly from the road and are far younger than the lake itself. 

  • Negit Island: is a volcanic cone that scientists believe to be around 2000 years old. It is composed of three lava flows and is an important nesting ground for many migratory birds. The lake levels fell around 1941, allowing a land bridge to temporarily form between the mainland and Negit Island. But, today, the water levels are too high to allow for easy access. It is only accessible by boat for part of the year. 
  • Poaha Island: is a volcanic island formed through a series of eruptions in the 17th century. Its name came from the word “Pa-o-ha” which is used to describe the hot springs and fumaroles on the surface. The island is within the central part of Mono Lake and is loosely shaped like an oval. It’s to Poaha Island that Mark Twain and his companions journeyed in his novel, Roughing It. 


Why is Mono Lake So Salty? 

Mono Lake has a very high salinity, nearly three times that of the ocean. This is due to the fact that the lake has no outlet. All escaping water leaves through evaporation, leaving behind salt and other chemicals that give the lake its distinctive look, smell, and salty quality. The lake also has a high pH level due to its structure, around that of a household glass cleaner (this makes the water very unsuitable for drinking). In an 1863 geographical survey, William Brewer described the chemistry of the lake in the following quote: 

The waters are clear and very heavy. When still, it looks like oil, it is so thick, and it is not easily disturbed. The water feels slippery to the touch and will wash grease from the hands, even when cold, more readily than common hot water and soap.


Animals in Mono Lake 

Mono Lake is an interesting and incredibly important ecosystem. It is home to trillions of tiny, black alkali flies and many brine shrimp. These small food sources feed the millions of migratory birds, such as California gulls, that visit Mono Lake every year. While visiting the lake, one might see some of the following birds:

  • California Gull
  • Eared grebes 
  • Osprey 
  • Yellow warbler 
  • Green-tailed towhee
  • Western tanager 
  • Lazuli bunting
  • Least Sandpiper 
  • White-faced Ibis
  • Sabine’s gull
  • Wilson’s Phalarope

The latter, the Wilson’s Phalarope, is one of the more notable guests at Mono Lake. These tiny shorebirds arrive in Mono Lake in the middle of the summer. They molt their feathers and double their weight while there, preparing for a three-day, 3000-mile flight to the saline lakes in South America. Interestingly, due to the lake’s saline content, it’s incapable of supporting fish.

Alkalai flies on the shore of Mono Lake
Image of the many alkali flies visitors can see around the lake


Mark Twain and Mono Lake 

The entertaining story of Mark Twain‘s visit to Mono Lake, and his journey out to Poaha Island, are recounted in his semi-autobiographical novel, Roughing It (published in 1872). At the beginning of Chapter XXXVIII, Twain writes of Mono Lake: 

This solemn, silent, sailless sea—this lonely tenant of the loneliest spot on earth—is little graced with the picturesque. It is an unpretending expanse of grayish water, about a hundred miles in circumference, with two islands in its centre, mere upheavals of rent and scorched and blistered lava, snowed over with gray banks and drifts of pumice-stone and ashes, the winding sheet of the dead volcano, whose vast crater the lake has seized upon and occupied.

The novel describes Twain and a few companions camping on the shore of Mono Lake and rowing out to Poaha Island, where they believed they would find a “spring of pure cold water, sweet and pure.”  
Unfortunately for the explorers, their rowboat became untethered, nearly trapping them on the island, twelve miles from shore. Without water or food, the men would’ve been faced with the need to swim through Mono Lake’s incredibly salty water. Twain wrote, incorrectly, that if one fell into the lake:

death would ensue in spite of the bravest swimming, for that venomous water would eat a man’s eyes out like fire, and burn him out inside, too, if he shipped a sea.

While fictitious, this quote does demonstrate how shocking  Mono Lake’s salinity is to the casual visitor. Luckily, one of Twain’s companion’s regained their small boat, and they returned to the mainland safely.

FAQs 

Can you swim in Mono Lake? 

Yes, despite the water’s salt content and its high pH level, it is possible to swim in Mono Lake. The salt makes it a very interesting experience due to the increased buoyancy that swimmers encounter. 

Does anything live in Mono Lake? 

Mono Lake is home to trillions of brine shrimp and alkali flies. But, it hosts no fish. Around the lake, visitors may also see some of the millions of migratory birds that visit its salty shores yearly.

What happens if you swim in Mono Lake?

If you swim in Mono Lake, you are likely to experience an unusual sensation of increased buoyancy. You might also find, as you exit the lake, that a layer of salt sticks to your hair and skin. It is important to keep the water out of your eyes and pay attention to any cuts (which may sting when they come into contact with the water).