Ontario Assessment File Database

Assessment Files contains the technical results from all exploration work done in the province of Ontario.

Data includes: details on location, property ownership, type of work done, commodities sought for each assessment file and a link to the PDF version of each file that is stored on GeologyOntario.

The database will assist exploration companies and individual prospectors in their efforts to locate new deposits within the Province of Ontario by allowing effective access to past exploration activity reports in Ontario.

This data is best viewed using Google Earth or similar Keyhole Markup Language (KML) compatible software. For instructions on how to use Google Earth, read the Google Earth tutorial.

[PDF]: portable document format [KML]: Keyhole Markup Language

Ministry contact: ndmminister@ontario.ca

Additional information

Tags
Geographic coverage
Ontario
Last Validated Date
February 26, 2026
Update frequency
Monthly

Ontario Assessment File Database

Learn more about accessing data using different formats.

Date range: No start date - February 5, 2026

  • WEB
    Data English

    Last Updated: February 5, 2026

    Explore
  • WEB
    Data French

    Last Updated: February 5, 2026

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Date range: January 1, 1890 - February 5, 2026

  • KML
    Assessment Files - KML English

    Last Updated: February 5, 2026

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