The 1976 Big Thompson Canyon Flash Flood
- Cedar Springs Reservoir
- Aug 10
- 1 min read
In the early evening of July 31, 1976, a near‑stationary thunderstorm unleashed an extraordinary 12–14 inches of rain—including about 7.5 inches in just one hour—over parts of Estes Park and Big Thompson Canyon
The flood storm transformed into a devastating wall of water, over 20 feet high, charging down the narrow canyon at roughly 15 miles per hour. This surge obliterated everything in its path, washing out U.S. Route 34, destroying 418 homes, more than 400 vehicles, and 152 businesses—with total damages estimated near $40 million (1976 USD)
Tragically, this catastrophic event claimed the lives of 144 people, injured over 250, and left 5 individuals missing. At the time, this stood as Colorado’s deadliest flash flood, prompting widespread changes in how emergency response and land-use in canyon areas are managed.
Why It Still Matters
The 1976 Big Thompson flood remains a poignant reminder of how destructive flash flooding can be—especially in steep, narrow canyons. It reshaped regional approaches to disaster preparedness, infrastructure resilience, and community awareness.
Resources for Further Reading
Wikipedia: 1976 Big Thompson River flood Wikipedia+11Wikipedia+11The Weather Channel+11
Wikipedia: Big Thompson River, including flood details Wikipedia+15Wikipedia+15Wikipedia+15
Denver7: Remembering the 1976 Big Thompson Flood (firsthand accounts, community impact) Weather.gov+5Denver 7 Colorado News (KMGH)+5UGA Extension+5
Weather.com: On This Date: The Deadly Big Thompson Canyon Flash Flood (storm and impact overview) U.S. Geological Survey+3The Weather Channel+3Wikipedia+3
Comments