After going through Yosemite and crossing the Sierra Nevada, the landscape become much more arid and desertic, it’s because the mountains stops the humid air coming from the ocean.

Sitting between the mountains at 2000 m, just after Yosemite, is Mono Lake, a really special lake on many aspect :

• its age : it has been there for probably a million year, and likely more
• it’s a terminal lake, it has no outlet (its surrounded by mountains) : the only way for water to leave is by evaporating, which happen a lot has the climate is hot and dry
• as water has been evaporating for almost a billion year, the lake has a high salinity, three times more than the ocean
• for the same reason and because the water sources flow through different kinds of rocks, the water is very alcaline : it has a lots of carbonates (its pH is around 10).

Mono Lake water feels sick and slippery when you touch it, a bit like salty soapy water. You could reproduce the same thing by mixing water with salt and baking powder. Because of this “thickness”, the surface is really flat, almost undisturbed by wind.

An other exceptional phenomenon happens in this lake. Fresh water run down underground from the mountains, go through volcanic rocks and get loaded with calcium. When it arrives in the carbonate-rich lake water, a chemical reaction happens : it precipitates in calcium carbonate, also known as limestone. It result in strangely shaped towers, now visible as the lake level as dropped by several meters. Those formations are called tufa.

The lake also have a unique biodiversity. It has a lot (really a lot) of flies “Akali Flies” who like alkaline water (and they are the best flies I’ve met : they fly away from you when you approach). Mono Lake also have its really own really small shrimp species, the Brine Shrimp.

Those abundant flies and shrimps make the lake a paradise for birds, several species stop there as a rest in their migration.

Because of the lake sources being used as water source for Los Angeles, the water level of the lake dropped, and the ecosystem almost collapsed. Hopefully, after a long fight, the protectors won and the water level is now regulated.