Boulder Fire

Wildfire in San Diego County, September 1970

Search for an address

Printed October 28, 2026 from www.firezones.info/fire/2605/boulder-fire-1970

Key facts

Started September 28, 1970
Contained Not recorded
Burned 12,830 acres
10th largest fire of 1970
Cause Miscellaneous
Open map

Where it burned

County

  1. San Diego County 12,828 acres

Acres are the land the fire burned in each county and community, and places where it burned less than an acre are not listed. Communities are cities, towns and the unincorporated places the Census Bureau names, so land outside any of them is counted only in its county.

The same land, other fires

Burned before

  1. 1911 Unnamed fire 1,058 acres in total · Cause: Lightning 595 acres shared
  2. 1928 Unnamed fire 48,613 acres in total · Cause: Miscellaneous 1,859 acres shared
  3. 1931 Unnamed fire 675 acres in total · Cause: Miscellaneous 648 acres shared
  4. 1932 Unnamed fire Cause: Miscellaneous 215 acres shared
  5. 1935 Unnamed fire 202 acres in total · Cause: Miscellaneous 79 acres shared
  6. 1939 Unnamed fire Cause: Miscellaneous 101 acres shared
  7. 1947 Unnamed fire 180 acres in total · Cause: Miscellaneous 178 acres shared
  8. 1949 Unnamed fire Cause: Miscellaneous 197 acres shared
  9. 1950 Conejos Fire 62,849 acres in total · Cause: Miscellaneous 3,775 acres shared
  10. 1956 Unnamed fire Cause: Lightning 127 acres shared
  11. 1956 Outside Origin #42 Fire 46,602 acres in total · Cause: Miscellaneous 3,755 acres shared
  12. 1961 Barta Fire 855 acres in total 91 acres shared
  13. 1967 Unnamed fire 7,094 acres in total · Cause: Miscellaneous 96 acres shared

Burned again

  1. 1972 Sill Fire Cause: Campfire 112 acres shared
  2. 1975 Devil Fire Cause: Campfire 230 acres shared
  3. 1993 Eagle Fire 5,204 acres in total · Cause: Campfire 315 acres shared
  4. 2002 Peak Fire Cause: Equipment use 245 acres shared
  5. 2003 Cedar Fire 270,686 acres in total · Cause: Equipment use 12,828 acres shared
  6. 2007 Witch Fire 162,070 acres in total · Cause: Miscellaneous 1,757 acres shared
  7. 2007 Mccoy Fire Cause: Miscellaneous 353 acres shared

And 5 more fires that burned less of the same land. Acres are the land each fire shares with the Boulder Fire, and fires that shared less than an acre are not counted. Some older or smaller fires may be missing, and a fire perimeter can include unburned patches. How to read fire history

Sources

Fire history
CAL FIRE Fire and Resource Assessment Program
Published 28 July 2026
Building damage
CAL FIRE Damage Inspection
Updated 19 October 2026

This site is independent and not affiliated with CAL FIRE or the CPUC, so for an official determination, check with the agency or your city or county. How we read the data