ZIP code 91773

Los Angeles County, including San Dimas

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Report created October 31, 2026 at www.firezones.org/zip/91773

Summary

  • Fire hazard severity zones

    Share of the land in each CAL FIRE hazard class

    1. Very High 3,292 acres · Local Responsibility Area 33%
    2. High 1,802 acres · 2 state, 1,801 local 18%
    3. Moderate 517 acres · 1 state, 516 local 5%
    4. Non-wildland 3,072 acres · Local Responsibility Area 31%
    5. Not mapped by CAL FIRE 1,151 acres · Mostly federal land 12%

    9,834 acres of land in all, 2 in the State Responsibility Area and 8,681 in the Local. State zones are the ones the State Fire Marshal designated, in effect since April 1, 2024. Local zones are CAL FIRE's 2025 recommendation, which each city or county adopts by ordinance and can make stricter. How to read fire zones

  • Fire history

    The 10 largest of 56 fires that burned here

    1. 2002 Williams Fire 38,119 acres in total · Cause: Arson 1,909 acres here
    2. 1960 Unnamed fire 22,736 acres in total 1,873 acres here
    3. 1919 San Gabriel Fire 54,610 acres in total 1,711 acres here
    4. 1957 Unnamed fire 461 acres here
    5. 1981 Mull Fire 668 acres in total 380 acres here
    6. 1927 Phillips No. 51 Fire 364 acres in total 355 acres here
    7. 1932 Morgan No. 24 Fire 550 acres in total 350 acres here
    8. 1975 Via Verde Fire 331 acres here
    9. 1971 Lodi Fire 343 acres in total 250 acres here
    10. 1955 Puddingstone Fire 251 acres in total 248 acres here

    And 46 smaller fires. The most recent was the 2021 Kellogg Fire, which burned 12 acres here. In all, 4,443 acres of ZIP code 91773 have burned. Acres are the land each fire burned here, and fires that crossed 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

Nearby areas

Communities in ZIP code 91773

Neighboring ZIP codes

  1. 91773 33% Very High · this area
  2. 91724 29% Very High
  3. 91740 29% Very High
  4. 91741 33% Very High
  5. 91750 29% Very High
  6. 91768 18% High · 4% Very High
  7. 91789 17% Very High

Sources

Fire hazard severity zones
CAL FIRE Office of the State Fire Marshal
State map published June 27, 2025, local map February 2, 2026
Fire history
CAL FIRE Fire and Resource Assessment Program
Published July 28, 2026

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