Great Salt Lake

The Great Salt Lake is a massive body of water in northern Utah. It is the largest saltwater lake in the Western Hemisphere. It is also the eighth-largest terminal lake in the entire world. A terminal lake is a lake that has no outlet. This means water cannot flow out through rivers or streams. Instead, water only leaves the lake through the process of evaporation.

This lack of an outlet creates a unique chemical process. Three major tributaries, the Bear, Weber, and Jordan rivers, flow into the lake. Every year, these rivers deposit approximately 1.1 million tons of minerals into the water. Because the water evaporates but the minerals stay behind, the concentration of salt increases. This results in high salinity, making the lake much saltier than the ocean. This high salt content also increases the water's density. Because the water is so dense, objects like humans can float very easily while swimming.

The lake is actually a small remnant of a much larger prehistoric system. During the Pleistocene Epoch, a massive body of water called Lake Bonneville covered the region. At its peak, Lake Bonneville was nearly as large as Lake Michigan. It was roughly ten times the size of the current Great Salt Lake. The lake covered much of Utah and parts of Idaho and Nevada. About 16,800 years ago, a large portion of this water escaped through Red Rock Pass in Idaho. This event caused cataclysmic floods. As the climate warmed, the remaining water dried up into several smaller lakes.

Human history with the lake involves many different explorers and settlers. In 1776, Silvestre Vélez de Escalante learned of the lake from the Timpanogos Utes. Early maps often confused the Great Salt Lake with Utah Lake. In 1824, Jim Bridger and Etienne Provost observed the lake independently. Later, in 1843, John C. Fremont led the first scientific expedition to the area. His reports influenced Brigham Young to settle the Salt Lake Valley in 1847. In 1850, Howard Stansbury conducted the first comprehensive survey. He even named Stansbury Island during his travels.

The lake's size changes constantly due to water levels and climate. In the 1980s, the lake reached a historic high. This caused flooding and damaged property on the eastern side. To help, the state built the West Desert Pumping Project in 1987. This project used three pumps at Hogup Ridge to move water into the desert. The goal was to increase the surface area to speed up evaporation. The project removed about 120,000 acre-feet of water before it shut down in 1989.

Today, the lake faces significant threats from drought and water diversion. In 2021, the lake fell to its lowest recorded area. This was lower than the previous record set in 1963. Scientists at Brigham Young University estimate the lake could dry up by 2028 without policy changes. Such a loss would impact the local climate and environment. For example, the lake helps create lake-effect snow. Shrinkage could also turn the lake bed into a source of toxic dust. This dust could potentially poison the air near Salt Lake City.

Despite these challenges, the lake remains a vital ecosystem. It provides a habitat for millions of native animals. These include brine shrimp, nematodes, and many types of waterfowl. The lake holds the largest staging population of Wilson's phalarope in the world.

It also supports unique life forms like stromatolites on its shores.

The lake is also a site of human engineering, such as the railroad causeway. This causeway was built in the 1950s by the Morrison-Knudsen company. Today, about 15 trains cross this route every single day.