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Lake Abert and Abert Rim were formed by tectonic movements in the Earth's crust causing it to rupture and split into mountains and basins.

Abert Rim is the longest exposed escarpment in America, stretching unbroken for 50 kilometres.

The water in Lake Abert is so corrosive that it would burn skin on contact.

Dust devil on Summer Lake. During the warmer months, Summer Lake dries up leaving behind a dusty salt flat.

The salty shoreline of Summer Lake. As the water in the lake evaporates, salt flats are left behind - here, the lake is still relatively full.

Lake Abert is Oregon's only saltwater lake. The water is so alkaline that it can only support brine shrimp, who live here in their millions.

This satellite image shows Summer Lake (middle, pale) and Lake Abert (right, green) within the shape of the Chewaucan Basin. The famous Crater Lake can also be seen to the left of the image.

For most of the year, Summer Lake is a large salt flat. Water levels in the marshlands are now being regulated by dikes to prevent too much water evaporating.

The highly alkaline water of the Summer Lake makes it difficult for plants to grow here.

Oregon's Outback is a huge desert expanse that surrounds Summer and Abert Lakes. The ground is very dry here, so irrigation circles are common for agriculture.

Summer Lake was once part of the larger Lake Chewaucan, which when it dried up left behind two salty lakes; Summer Lake and Lake Abert.

Salt is deposited on the dry bed of Summer Lake as the lake water evaporates away leaving the minerals behind.

Summer Lake is part of what is known as Oregon's Outback - a cool desert region that is part of the Great Basin.

Abert Rim is considered the longest exposed escarpment in the United States. Seen here with Lake Abert in the background.

The Great Basin covers an area the size of Spain and is an entirely closed drainage basin meaning that none of the water within the basin ever flows out to the sea.

For most of the year, Summer Lake remains a dusty salt flat, as the shallow water evaporates leaving behind high concentrations of dried minerals on the lake bed.

A sign near Lake Abert shows the extent of the original Lake Chewaucan in orange, encompassing both Summer Lake and Lake Abert.

The dry bed of Lake Abert reveals the build-up of minerals in the water - a thick crust of salt is left by the evaporated water.

Abert Rim overlooks Lake Abert. This escarpment was created by fault-block topography commonly seen across the Great Basin region.

A group of American white pelicans on Summer Lake.

Parts of Summer Lake are kept filled by dikes that hold water in the lake to encourage wildlife to stay here year round.

A great egret at the Summer Lake Wildlife Area. This refuge is very important for birds in the region.

Ducks at the Summer Lake Wildlife Area. Ducks flock to the wetlands, providing an opportunity for hunters in the region. In the background is a white-faced ibis, a local species.

A pair of American avocet in breeding plumage, Summer Lake Wildlife Area. More than 250 species of birds call this wetland home.

A group of white fronted geese arrive at Summer Lake. This region is a vital stopping point for migrating birds.

Wild rabbits are among the small mammals that live around Summer Lake.

The Ana Reservoir in Summer Lake Wildlife Area is fed fresh water by the Ana River and provides plentiful fish for anglers in the region.

Brine shrimp, also known as Sea-Monkeys, are the only creatures that can survive in the salty water of Lake Abert.

Magnificent wild bald eagles can be spotted in Summer Lake Wildlife Area.

Summer Lake and Lake Abert are vital stopping points for birds migrating along the Pacific Flyway. Multiple migration routes cross America, shown on this map with the Pacific Flyway in green.

A group of pelicans at Summer Lake. The wildlife refuge welcomes hundreds of different species of birds at all times of the year.

Huge flocks of snow geese arrive at Summer Lake each year on route between the Arctic and Mexico.

Cave 5 excavations 2003. It was not until 2007 that the first coprolite was discovered in the Paisley Caves. Until then, there was no evidence here that humans had lived here before 7,000BC.

When early humans lived here, up to 14,000 years ago, the Paisley Caves looked out over lush grasslands fed by Lake Chewaucan. Today, the region is desolate but still beautiful.

Cave 2 stratigraphy. The cave floor has built up over millennia, each different coloured layer revealing something about the era it was laid down.

Paisley Caves Site Overview from west. When early humans lived in these caves up to 14,000 years ago, the desert around Summer Lake was a grassy plain that teemed with life.

Paisley Caves 3-4 and 5. Teams from the University of Oregon work at the Paisley Caves excavation site searching for further evidence to prove how early humans lived here.

The discovery of coprolites in the Paisley Caves in 2007 attracted a good deal of media attention, as the finds contradicted all the theories about how and when early humans arrived in North America.

Lead archaeologist Dennis Jenkins with a coprolite. Jenkins has been working on the Paisley Caves excavation since it started in 2002.

Human coprolite 1374-PC-5-5D-31-22. This coprolite, or fossilised human extement, is likely to be from some of the earliest humans in America, some 14,000 years ago.

Coprolite collection procedures. As with all archaeology, it is very important to carefully handle the coprolites in order to preserve them for analysis.

Collecting coprolites in Cave 2. Coprolites, or fossilised human excrement, found in the Paisley Caves reveal that people were living at Summer Lake up to 14,000 years ago.

Suiting up to collect coprolite in Cave 2. The discovery of coprolites, or fossilised human droppings, in the Paisley Caves has spurred an extensive excavation project at Summer Lake.

Stratigraphic Profiling of Unit 5-12. Archaeologists measure different layers of the cave floor - each layer contains material from different years which reveals what Summer Lake was like at that time.

Removing boulder at Cave 5. The excavation work at Summer Lake began in 2002, with new artefacts still being found.