There are stories buried under the plains that do not look like stories at first.
Sometimes they look like a dry creek bed. Sometimes they look like a line of cottonwoods standing against the wind. Sometimes they look like sand, cracked earth, buffalo grass, tamarisk, Russian olive, and the faint green trace of water that may not be visible on the surface but is still moving somewhere below.
In southeastern Colorado, water has always been more than water. It has been survival, direction, settlement, conflict, memory, and promise. Long before county lines, wind farms, irrigation ditches, reservoirs, compact lawsuits, and water court filings, the Arkansas River and the sandy creeks feeding it shaped the lives of people, animals, grasslands, and trees.
Big Sandy Creek, known to many locally as Sand Creek, is one of those waterways that tells a complicated story. It may be dry on the surface for long stretches, but beneath the sand, water has long moved through the valley fill. That underground water helped shape the creek bottoms, the grasses, the cottonwoods, the wildlife, and the human history tied to this part of Colorado.
The question, then, is not simply, “Where did the water go?”
The better question may be, “What changed?”
Before southeastern Colorado was fenced, plowed, settled, and governed by modern water law, the plains were shaped by fire as much as by rain. Lightning fires swept across the grasslands. Indigenous people also used fire intentionally and skillfully, not as destruction but as land management. Fire could renew grass, move bison, improve hunting conditions, clear old growth, and keep the prairie open. It was one of the tools by which Plains tribes understood and lived with the land.
The Cheyenne and Arapaho people, along with other Plains tribes who traveled, hunted, camped, traded, and lived across this region, understood water in a way that modern people sometimes forget. On the plains, water was not taken for granted. Camps were made with knowledge of creeks, springs, rivers, grass, shelter, and seasonal movement. The Arkansas River was not merely a blue line on a map. It was a corridor of life and travel. Big Sandy Creek was not merely a drainage. It was part of a larger living landscape.
That truth is impossible to separate from the history of Sand Creek.
On November 29, 1864, Cheyenne and Arapaho people were encamped along Big Sandy Creek when U.S. troops attacked in what is now remembered as the Sand Creek Massacre. The site remains sacred ground for Cheyenne and Arapaho descendants. Today, the Sand Creek Massacre National Historic Site preserves not only the memory of that atrocity, but also the landscape itself—the creek bed, the prairie, the cottonwoods, the silence, and the long shadow of what happened there.
Those cottonwoods matter.
Along the Big Sandy, cottonwoods are more than trees. Some of the oldest trees near Sand Creek may have been seedlings or saplings near the time of the massacre. Others became established in later flood years, when high water scoured the channel, deposited fresh sediment, and briefly raised the water table enough for young cottonwoods to take root. They are part of the natural history of the creek, but also part of its human memory.
Still, cottonwoods are thirsty trees. A mature cottonwood can use a great deal of water, especially when its roots reach shallow groundwater. Anyone who has walked a creek bottom in July understands the tradeoff. The shade is welcome. The birds are there. The soil is cooler. The leaves tell you water is near. But the same tree that gives shelter is also drawing moisture from the ground and releasing it through its leaves.
That process is called evapotranspiration, which is a large word for something very plain: plants pull water from the soil and send it back into the air.
Cottonwoods do this. Willows do this. Grasses do this. Crops do this. Tamarisk and Russian olive do this too.
The difference is that cottonwoods are native riparian trees. They belong to the creek bottoms of the plains. Tamarisk, also known as salt cedar, does not. Russian olive is also non-native. Both have spread along waterways across the West, often forming dense stands that crowd native vegetation, alter habitat, and consume water from shallow groundwater systems.
That is where the modern water conversation begins to overlap with the old history of the plains.
In the past, frequent fire, grazing by bison, periodic flooding, drought, and natural disturbance helped determine where trees could grow and where grassland remained open. Woody plants were generally more limited to draws, creek bottoms, river corridors, and protected places where moisture allowed them to survive. Fire helped keep the prairie from becoming overrun with trees and shrubs.
Modern settlement changed that pattern. Fire was suppressed. Bison were nearly eliminated. Cattle replaced them but grazed differently. Fields were plowed. Roads, ditches, railroads, towns, reservoirs, wells, and fences changed how water moved across the land. Some floods were controlled. Some channels shifted. Groundwater was pumped. Irrigation expanded. Drought came and went, as it always has, but now the land receiving that drought was not the same land it had been centuries earlier.
Then came invasive riparian species, especially tamarisk.
Tamarisk was introduced to the United States in the nineteenth century and was once planted for shade, windbreaks, and erosion control. Like many ideas that seemed good at the time, it later brought a bill no one wanted to pay. Across parts of the West, tamarisk spread along rivers and creeks, thriving in salty soils, drought conditions, and disturbed waterways. Once established, it could grow thickly enough to change the character of a stream corridor.
In southeastern Colorado and western Kansas, where every acre-foot of water matters, the question of riparian vegetation is not small. Dense stands of thirsty trees and shrubs can contribute to water loss. Removing or reducing non-native species such as tamarisk and Russian olive may help retain some water in certain places, especially where they are tapping shallow groundwater.
But nature does not hand out simple answers.
Cutting trees does not automatically bring back a running creek. Water is also affected by rainfall, drought, soil, irrigation, groundwater pumping, reservoirs, stream compacts, land use, and whether native vegetation returns after invasive plants are removed. A creek that is dry on top may still be moving water underground. A river that once spread wide across a floodplain may now be narrowed, diverted, measured, litigated, and managed.
The Arkansas River knows that story well.
For centuries, the Arkansas River served as a landmark, a route, a borderland, a gathering place, and a source of life. The Big Timbers area near present-day Lamar was known as an important camping and trading place along the Arkansas, used by Cheyenne and Arapaho people and later tied to Bent’s Fort, the Santa Fe Trail, trade, military movement, and settlement. Where there was timber on the plains, there was usually water. Where there was water, there were people.
That is one reason the old-timers notice trees.
A line of cottonwoods on the plains is a sign. It says something about what is happening underground. It marks a creek, a seep, a drainage, or a place where water once came often enough to let roots survive. But a thickening wall of invasive tamarisk or Russian olive can tell a different story—one of disturbance, changed flow, and a riparian system out of balance.
So perhaps the old question deserves to be asked again, carefully.
How much water is being used by the trees and shrubs along our creeks and rivers? How much of that vegetation is native and historically part of the landscape? How much is invasive? How much changed when prairie fires stopped doing the work they had done for centuries? How much water might remain in the ground or stream system if non-native species were reduced and native grasses, willows, and cottonwoods were better balanced?
Those are not simple questions, and they should not be treated like simple questions.
Cottonwoods are not the enemy. Along Sand Creek, they are witnesses. They are habitat. They are shade. They are part of the sacred and historical landscape. But they are also water users.
Tamarisk and Russian olive are different. They are non-native species that have earned serious attention across the West because of their effects on water, habitat, and stream corridors. In some places, removal projects have been used not as a cure-all, but as one tool in broader river restoration.
The old prairie was never empty. It was managed, burned, grazed, traveled, hunted, remembered, and lived upon. Its waterways were never just waterways. They were the threads that tied together grass, people, animals, trees, weather, and survival.
Today, when we look at a dry creek bed in Kiowa County or a crowded river bottom along the Arkansas, we are not just looking at what is there. We are looking at what has changed.
Water still moves beneath the sand.
The land still remembers fire.
And somewhere between the cottonwoods, the tamarisk, the old creek channels, and the stories handed down by those who have watched this country longer than most, southeastern Colorado is still asking the same question it has always asked:
How do we live with the water we have?
