California Tree Mortality High Hazard Zones for Wildfire Safety

High Hazard Zones identify California areas where dead trees directly threaten people, property, and infrastructure, heightening wildfire and falling tree risks. The data is designated by state and local governments for prioritizing tree removal under a 2015 emergency proclamation. It is updated annually, with the latest official release as of June 2019 being version HighHazardZones19_1.

Use Cases

• Analyze the spatial overlap of designated High Hazard Zones with property and infrastructure assets to prioritize safety interventions.
• Model wildfire risk by correlating zones of high tree mortality with historical fire perimeters and fuel data.
• Support community planning by identifying zones considered to have the highest potential safety issue to people and buildings.
• Track annual updates to the High Hazard Zones layer to monitor changes in designated priority areas for tree removal.

Strengths

• Data is designated by state and local government authorities for official safety prioritization.
• The service is updated annually, providing a mechanism for current information.
• Derived from a specific gubernatorial emergency proclamation on October 30, 2015, providing clear legal and policy context.

Limitations

• The sample data and specific column schema are unavailable, limiting understanding of the data's internal structure.
• The latest described version is from June 2019, which may be temporally stale relative to current tree mortality conditions.
• The 'other-license-specified' license requires users to investigate specific terms before use.

Provenance

Source

State of California, California Department of Forestry and Fire Protection (CAL FIRE).

Collection Method

Identified by public agencies pursuant to the California Governor's Emergency proclamation of October 30, 2015.

Time Range

Data reflects conditions as of the latest release (e.g., HighHazardZones19_1 from June 2019).

Freshness

Updated annually; last platform update recorded on 2026-03-23.

Geography

State of California, focusing on areas with coinciding tree mortality and assets to be protected.