06/03/2026
Starting on June 3 and stretching for several days, the Great Pueblo Flood of 1921 was one of the most devastating natural disasters to ever take place in Colorado. As a slow moving storm with heavy rains filled canyons and low-lying areas surrounding this southern Colorado city, a huge amount of water would ultimately travel down Arkansas River and Fountain Creek, hitting the city of 42,000 residents where the two flows converged and sweeping away an estimated 600 homes, causing $20 million in damages (about $331 million today).
While the scene was documented via photography and has been studied in-depth over the years, one big question remains – how many people did the Great Pueblo Flood of 1921 kill?
Estimates vary wildly when it comes to the death toll resulting from the flood. In a 2021 report from the National Weather Service, the organization states that "a few hundred fatalities occurred as people were swept down the river by the rushing torrents of water," going on to state that because many bodies were never recovered, "the exact death toll is unknown."
News sources in decades since the disaster have also been unable to land on a precise death toll that could be widely accepted.
The local Pueblo Chieftain newspaper once totaled the official death toll number at 104 killed, noting that the true number was likely over 600, with even that being a conservative estimate. Meanwhile, the Colorado Springs Gazette reportedly stated that 132 bodies were split between two morgues at the time, also noting that many more dead were discovered in mud and debris downstream. A reporter from History Colorado tracked down an official list of 78 deaths that was reported in the Pueblo Star-Journal in 1938, as well as three other estimates by the Pueblo Chieftain – "more than 250" in 1994, "more than 200" in 1981, and as low as 120 in 2011. The death toll of 78 was also one noted by the United States Geological Survey in 1922 and republished by The Associated Press, though their report also referenced many bodies that were swept downstream and not recovered. A Harvard master's thesis on the topic speculates that the death toll could be as high as 1,500.
In short, a true number of deaths related to the Great Pueblo Flood of 1921 isn't very clear – probably a lot, but that's proven extremely difficult to confirm by official means.
According to the National Weather Service, as the flood hit, water rose to close to 15 feet above some sidewalks in town. Other reports state that the flood was as deep as 27 feet.
The fastest wave was the first wave, hitting the nearby area of Florence at 16 miles per hour, with a flood crest discharge of 9,000 cubic feet per second.
To put that in perspective, SnoFlo.org states that average discharge of the Arkansas River above Pueblo is about 473 cubic feet per second – but wait, it gets wilder.
By the time a flood wave actually hit Pueblo, water was traveling at 10 miles per hour with a massive discharge of 103,000 cubic feet per second. La Junta would be hit a bit later, with a wave that was moving at 3.7 miles per hour, but with a discharge of 200,000 cubic feet per second. As might be expected, absolute devastation took place, as water, mud, and debris rushed through residential areas and city streets.
Bridges were destroyed and buildings were swept away in a scene of chaos that took place under the cover of night, ultimately impacting more than 300 square miles of land. To add to the problems, the destruction of telephone lines made it nearly impossible for Pueblo to communicate with the rest of the state.
Flood waters would eventually recede, and Pueblo would move forward by improving infrastructure of the city to prevent a similar situation from happening again, literally changing the path of the Arkansas River. Clean-up was extensive and thousands of people were left homeless. The question of the true death toll of the disaster would remain – how many people were killed in the Great Pueblo Flood of 1921?
Today, there's still no definitive answer. Likely a number that falls between 78 and 1,500 but given that bodies were swept away and buried in mud miles downstream, a true calculation has proven impossible.
One key contributing factor is the demographic of those likely impacted by the disaster – poor immigrants. Many of those in this local population had little ties to the area in terms of friends and family that could report them missing, making it difficult to determine who had disappeared during the flooding after the fact. This remains a key factor blamed today for why casualty numbers vary so wildly, further complicated by how some bodies were found far from where they would have originally been pulled into the water flow – in other words, the search area was massive, plus, burial in mud and debris is thought to have covered some bodies entirely.
Without an official death toll, it's hard to tell whether or not this was the deadliest natural disaster in Colorado's history, but there's a case to be made that it could be.
The closest weather event in terms of death would be the Loveland-area Big Thompson Canyon Flood of 1976, with a confirmed death toll of 144 people, also blamed for the destruction of close to 500 buildings. Whether or not the Great Pueblo Flood of 1921 was even deadlier than this will likely never be known for sure.
Today, the hunt for mass graves that may contain the bodies of those killed in the flood continues, with a major breakthrough in the search taking place in May of 2021. With morgues reportedly overrun in days surrounding the deadly flood amid a lack of air conditioning and a shortage of refrigeration units, bodies were reportedly buried en masse in large trenches.
In 2021, a team of students from the Colorado School of Mines used a non-invasive mobile ground penetrating radar unit to find a series of 3-foot-deep trenches at the local Roselawn Cemetery, thought to be dug by hand and as fast as possible. These trenches contained human remains, many of which are thought to be of victims of the 1918 Spanish Flu and of the 1921 Pueblo Flood. Whether or not these remains could lead to a more accurate death toll related to the flood is to be determined, though the ambiguous nature of their origins coupled with a heavy state of decay could keep a definitive answer difficult to find.
