Los Angeles Nearly Killed This Ancient Lake Until a Lawsuit Saved California’s Tufa Towers

The Mono Lake, California

When LA’s water pipes reached Mono Lake, nobody expected a fight. But as the ancient lake shrank and its stone towers emerged, scientists and locals sued the nation’s second biggest city.

The David vs. Goliath court case changed water law forever. Here’s what happened, and how you can visit this amazing lake today.

The Oldest Lake In North America

Mono Lake has collected water for at least 760,000 years, making it one of North America’s oldest lakes. It predates the massive volcanic eruption that reshaped the region long ago.

The lake sits in a basin formed when the earth’s crust sank 11,000 feet lower than surrounding land. This natural bowl collects water flowing from the mountains.

During the ice age, the lake grew five times larger than today. Ancient shorelines remain visible on surrounding mountains nearly 500 feet above the current water level.

The Limestone Spires

Springs at the bottom of Mono Lake push calcium-rich freshwater upward. When this freshwater meets the lake’s carbonate-filled water, a chemical reaction occurs.

Calcium bonds with carbonates to create limestone. This limestone builds up around each spring like a growing stone fountain.

These underwater formations grow very slowly, just one foot every hundred years.

When Los Angeles Drained Mono Lake

In 1941, Los Angeles needed more water. Engineers diverted streams that normally flowed into Mono Lake, sending water 350 miles south to the city.

By 1982, the lake had lost half its volume and dropped 45 feet in depth. With less water entering but evaporation continuing, the remaining water grew twice as salty.

As the shoreline receded, the underwater tufa towers became exposed, revealing formations that had been hidden for centuries.

Citizens Fight For Mono Lake’s Survival

Biologist David Gaines saw the lake’s decline and took action. In 1978, he started the Mono Lake Committee, which grew to include 20,000 members.

The National Audubon Society joined their lawsuit against Los Angeles in 1979. By 1983, the case reached California’s highest court.

The court ruled that environmental protection matters as much as human water use, a decision that changed California water laws in general.

Volcanic Islands Rise From The Lake

Two islands break Mono Lake’s surface. Both Negit and Paoha formed through volcanic activity within the past 2,000 years.

The larger island, Paoha, formed when underground magma pushed the lakebed upward until it rose above water around 1700. Parts of the island erupted with dark volcanic rock about 300 years ago.

Negit Island appears completely black from shore due to its volcanic composition.

The Soap-Like Lake

Mono Lake water feels slippery like soap from water 2.5 times saltier than the ocean.

The lake has no outlet, so every mineral washed in over thousands of years stays trapped. As water evaporates—about 45 inches yearly—these minerals become more concentrated.

The result is extremely alkaline water with a pH of 10, similar to ammonia. This harsh environment explains why no fish live here, though specialized creatures have evolved to thrive instead.

A Delicate Ecosystem

Mono Lake’s entire ecosystem relies on just three key species, much simpler than most natural systems. Microscopic green algae bloom each spring, turning parts of the lake bright green.

These tiny plants become food for everything else. Specialized brine shrimp—found nowhere else on Earth—eat this algae.

By summer, 4-6 trillion of these tiny creatures fill the lake. Alkali flies complete the trio, with larvae feeding underwater before emerging as adults.

The Remarkable Alkali Flie

Along Mono Lake’s shores, alkali flies do something amazing: they walk directly into the water without getting wet. These flies have water-repellent bodies that create protective air bubbles around them underwater.

This adaptation lets them eat algae growing on submerged rocks and lay eggs safely.

The native Kutzadika’a people even ate these nutritious insects, calling themselves “fly eaters” in their language.

Millions Of Birds Depend On Mono Lake

Every year, nearly two million migrating birds stop at Mono Lake while traveling the Pacific Flyway. They arrive hungry after flying hundreds of miles.

The lake offers plenty of protein-rich brine shrimp and alkali flies. Some birds, like Wilson’s Phalaropes, gain up to 60 percent of their body weight during their brief visit.

About 50,000 California Gulls nest on the lake’s islands each spring. In fall, up to 1.5 million Eared Grebes arrive, sometimes doubling their weight before continuing their journey.

Saving The Tufa Towers

California created the Mono Lake Tufa State Natural Reserve in 1981 to protect the limestone formations. This prevented damage from climbing and vandalism.

In 1994, after 44 days of hearings, state officials limited Los Angeles’ water diversions. They ordered the lake must eventually rise 17 feet higher to reach a healthy level of 6,392 feet above sea level.

Progress is slow, and the lake is still about 8 feet below the target in 2024.

Visiting Mono Lake Tufa State Natural Reserve

The reserve sits on Highway 395, 13 miles east of Yosemite National Park near Lee Vining, California. You’ll pay $3 per person (children under 16 free) with National Parks passes accepted.

Access the South Tufa area via Highway 120 East, 5 miles from Highway 395. The park stays open year-round with no set hours, and free guided tours run daily during summer, weekends in winter.

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