On Saturday, Oct. 17, 2020, at 12:22 p.m., the Boulder County Sheriff’s Office Communications Center received a report of a one-acre wildfire outside of Jamestown in the vicinity of the CalWood Education Center. This fire would soon become the Cal-Wood Fire. Of note, a Red Flag Warning had just gone into effect that day at noon The fire burned approximately 10,112 acres and is the largest fire by acreage in Boulder County’s recent history.
On Sunday, Oct. 18, 2025 around 12:30 p.m., the Communications Center received a report of a second wildfire outside of Ward in the area of Lefthand Canyon and Spring Gulch. This fire would become the Lefthand Canyon Fire. The fire burned 460 acres. There was minimal fire behavior due to snowy and cold conditions.
The fires prompted evacuation orders for nearly 4,925 people. Approximately 1,800 people and 967 animals were sheltered due to the fire evacuations. Twenty homes and 2 cabins were destroyed in the Cal-Wood Fire.
Cal-Wood Post-Fire Flood Risk Meetings
Boulder County invited all homeowners and residents of the Left Hand Creek West area And South St. Vrain Creek area to attend one of two Cal-Wood post-fire flood risk virtual meetings in April 2021. The meetings were free and open to the public.
The Cal-Wood Fire not only burned trees, lichen, and soil, but in severely burned areas the potential for hillslope erosion could cause small or large landslides and debris flows in a flash flood scenario. Post-fire flood risks were discussed at the meetings, including how residents and visitors can prepare, stay alert, and be forewarned of potential risks.
Presentations from the National Weather Service, Boulder County Parks & Open Space, Boulder County Office of Disaster Management, local fire departments, and Left Hand Watershed Center explained how residents can sign-up with the Everbridge alert system, be prepared, and stay informed.
- Presentation: National Weather Service – Flood After Fire
- Presentation: Boulder County – Heil Valley Ranch Cal-Wood Fire Recovery
- Presentation: Boulder OEM Cal-Wood Post-Fire Preparedness, April 2021
- Presentation: National Weather Service Post-Fire Preparedness, April 2021
- Website: Boulder County Office of Disaster Management
- Website: The Watershed Center
- Website: Boulder County Everbridge Alert Sign-Up
Heil Valley Ranch Cal-Wood Fire Recovery
Recovery work is mostly complete at Heil Valley Ranch. View the Parks & Open Space Heil Valley Ranch Cal-Wood Fire Recovery webpage.