Tufa Architecture: Chemistry as Landscape

What you are looking at in the lake is not rock that was exposed by erosion. It is rock that was created.

The tufa towers at Mono Lake are limestone columns that formed over centuries in an unusual meeting of chemistry. Freshwater springs on the lake floor carry dissolved calcium. The lake water itself is highly alkaline and carries dissolved carbonate. Where the spring water rises up through the lake floor, calcium meets carbonate, and the reaction deposits limestone. Not quickly. Column by column, year by year, century by century. The towers you are looking at are the accumulated record of springs that have been flowing, in some cases, for a very long time.

Until nineteen forty-one, none of this was visible. The towers were underwater, growing in the dark. That was the year the Los Angeles Department of Water and Power began diverting the streams that fed the lake. As the water level dropped, the towers emerged. They looked ancient because they were. The most-photographed features of Mono Lake had never been seen by anyone until the city started draining it.

The water in the lake is about two and a half times saltier than the ocean and ten times more alkaline. Almost nothing can live in it, except two things: the alkali fly and a species of brine shrimp called Artemia monica, which exists nowhere else on earth. Together, these two creatures sustain an ecosystem that feeds approximately two million migratory birds each year, including about eighty percent of California's breeding California Gulls.

The lake that looks inhospitable sustains a migration.