What Makes the Salt River Salty?
There are only so few places in the world where one can go salt river rafting as it’s not exactly a common occurrence to find salty rivers.White water rafting AZ is an extremely thrilling and enjoyable experience, one that countless people enjoy every year whether that is by swimming, tubing, kayaking, or doing some Salt River white water rafting.
Though, with as many people that enjoy the Arizona Salt River, very few actually understand why the fresh water of the Gila River, which turns into the Salt River Tributary, becomes salty to begin with once it leaves the White Mountains. The interesting thing is there is a little known reason as to why, which is even less common throughout the rivers of the world.
*Updated for 2026 — Learn why the Salt River in Arizona is salty and how the Tamarisk tree played a pivotal role.
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The Tamarisk Salt Cedar: The Thirsty Tree
The Salt Cedar, also known as the Tamarisk, is a plant that lines the Salt River. It was originally introduced for several good reasons: to prevent topsoil erosion, reduce riverbank erosion, and even slow down evaporation from the river itself. The Tamarisk tree is native to dry climates in the Middle East, Asia, and parts of Africa. When introduced to Arizona, the plant thrived in its new environment, and at first, there were no apparent negative side effects.
However, over time, the Tamarisk began to spread uncontrollably, replacing areas where forests of cottonwoods and willows once thrived along the river. These trees were meant to protect the riverbanks and soil, but their introduction would ultimately change the landscape in unexpected ways.
What Makes the Salt Cedars Salty
The Tamarisk has an incredible ability to draw salt from the earth through its roots. This salt is then stored in the leaves of the tree. As wind blows and rain falls, the salt is knocked off the tree and falls into the river, adding to the saltiness.
This process is the key reason the Salt River has its characteristic salty taste, especially in certain sections where the Tamarisk grows abundantly. The Tamarisk tree’s salt-releasing process makes the Salt River one of the few rivers in the world that can claim such unique conditions.
A Mistake from Long Ago
Farmers and miners thought it was a brilliant idea to introduce the Tamarisk tree. It required little water, preserved topsoil, protected river banks, and even helped to shield crops and homes from wind. Additionally, the trees helped cover the river, theoretically preventing water evaporation. But decades later, the Tamarisk had taken over, and its unchecked spread made it difficult to find any remaining natural vegetation where the Tamarisk thrived.
As the Tamarisk spread, experts began to wonder how much water was being lost through the stomata of the Salt Cedars. These trees were clearly using up significant water resources, leading to concerns about the long-term effects on the river ecosystem and water supply.
Efforts were made to remove the Salt Cedars, but they were much harder to eliminate than to introduce. The Tamarisk’s seeds would linger in the soil until rain fell, causing new trees to sprout up in place of those that had been removed. This cycle continued for years, creating a persistent problem that took a long time to address.
What Scientists Discovered About the Tamarisk
In the mid-1980s, scientists discovered an interesting fact: the Tamarisk hadn’t killed off the natural vegetation, as many initially thought. Instead, the local plants died off because they couldn’t survive in the new soil conditions that the Tamarisk altered. Interestingly, where native vegetation had a chance to survive, fewer Tamarisk trees were found. It became clear that the Tamarisk depended on the death of local plants for its survival.
The tree was actually doing some positive things too: it preserved the topsoil and prevented riverbank erosion as it thrived in the region. The tree also helped reduce the evaporation of the river more than the amount of water it consumed for its own hydration.
So, in the end, we now know that the Tamarisk tree contributed significantly to the formation of the landscape that defines the Salt River. While it wasn’t part of the original ecosystem, it helped shape the river’s salty nature and created the river’s unique features that we enjoy today.
Salt River Rafting: A Unique Experience
Without the Tamarisk, Arizona rafting on the Salt River would be completely different. The saltiness brought by the Tamarisk gives the river a unique character that sets it apart from other rivers across the world. Whether you’re rafting, tubing, or simply enjoying the landscape, the Salt River offers an unforgettable experience.
Wilderness Aware Rafting offers incredible trips on the Salt River, allowing visitors to experience this rare river firsthand. Whether you’re seeking a calm, scenic float or a more thrilling whitewater adventure, the Salt River provides a one-of-a-kind rafting experience, made even more special by its salty waters.
FAQ About the Salt River and Tamarisk Tree
The Salt River’s saltiness comes from the Tamarisk tree, which draws salt from the soil and stores it in its leaves. When the leaves fall or get knocked off by rain or wind, they release the salt into the river, raising the salinity levels.
The Tamarisk tree was introduced to prevent erosion and reduce evaporation. Over time, it became invasive, altering the local vegetation and contributing to the river’s salty water.
Farmers and miners introduced the Tamarisk tree to help protect topsoil, prevent erosion, and slow evaporation. Though it performed these tasks, it spread uncontrollably and altered the river’s ecosystem.
Yes, the Salt River is still a popular spot for rafting, tubing, and kayaking. The saltiness of the river adds a unique twist to the experience, making it one of the most unusual rafting destinations in the world.
