Two million years ago, as glaciers carved much of North America, torrential rains flooded what is now the Western United States, forming vast lakes across the region. The only remnants of that era are millions of saline ponds, some so small that over a hundred can be concentrated into a square kilometer. These lakes are now quickly shrinking. With less runoff from snowpack, and more water being diverted for agriculture, the lakes’ levels are rapidly decreasing, becoming even higher in salt content.

These saltwater landscapes of the West are in a constant flux, transforming from low salinity chartreuses and cyans to alkaline magenta, finally settling into evaporated salty white wastelands. Soaring in a small plane above the landscapes, photographer Aya Okawa captures these unique ecosystems at different stages of their progressions, as salt becomes more concentrated.

One of Okawa’s shots features the pale, barren expanse of Owen’s Lake. Once bright blue, the lake was a haven for migratory birds. Birds use saline lakes as crucial stopover points on their long migrations, refueling there by gorging the plentiful brine flies and brine shrimp. But since the 1913 diversion of Owens River, Owen’s Lake has become an expansive wasteland. Lake bed dust, as much as four million tons a year, carries carcinogens like cadmium, nickel and arsenic on the wind and into the lungs of nearby residents.

At Owen’s Lake, we see the final death of a fertile ecosystem; poisoning rather than nursing life.

Mono Lake, just over 100 miles to the north, narrowly avoided a similar fate. But thanks to a 1994 order from the California State Water Resources Control Board that required the Los Angeles Department of Power and Water to stop withdrawing water until the lake’s surface rose 17 feet, Mono Lake is slowly recovering. Still, at 10 feet under that goal, the ecosystem remains vulnerable, and its levels are at an historical low.

Step further back into a salt lake’s lifespan and you’ll reach the Great Salt Lake. The natural habitat offered by the lake is rapidly decreasing as snowmelt and river inlets are diverted by development up basin from the lake. Utahns consume more water than other arid regions. Consequently, the Great Salt Lake has half the amount of water it did in the 18^th century.

Okawa captures both pink and green in San Francisco’s salt ponds. Before the 1940’s, the salt ponds were green marshland. Over 50 years they were coaxed by developers into shades of rust to concentrate salt and produce ice-melt for our roads, taste to our foods. But in 2003 the ponds, so bright that NASA used them as a marker from space, became part of a massive conservation project. 15,100 acres were sold to a group of federal and state resource agencies and private foundations to be reverted to marshland. Today the marshland supports a variety of species, including pelicans, seals and salmon. From brick red to a vibrant green, San Francisco’s salt ponds are one of the few saltscapes that has reversed its trajectory.

But the many land-locked salt lakes of the West likely won’t fair as well. As they dry and become even more alkaline, the lakes phase from emerald tones into residual basins of bubblegum. In the near future, many of these saltscapes could look like the dried-up Owen’s Lake, empty, monochromatic veins weaving across a desolate landscape. –Luna Anna Archey, associate photo editor

Aya Okawa is an award-winning photographer and visual anthropologist who enjoys shooting environmental transformation, abstract patterns, and documenting human impact on the natural world. Her work has been printed in National Geographic, the Washington Post, The Guardian and the book Spectacle. Follow her on Instagram. Email High Country News at [email protected] or submit a letter to the editor.