Ontario Drill Hole Database

The Ontario Drill Hole dataset contains index information for more than 126,000 percussion, overburden, sonic and diamond drill holes from assessment files on record with the Mines and Minerals Division.

Data includes location, company name, company hole number, hole orientation, hole depth, and overburden depth if applicable. The presence of assay results within cutoff values for gold, silver, copper, zinc, lead, nickel and platinum group elements is noted. Source assessment file numbers are captured for cross referencing with the assessment file database (ODHD).

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.

*[KML]: Keyhole Markup Language

Ministry contact: ndmminister@ontario.ca

Additional information

Tags: Economy and Business Economy and Business

Environment and Nat... Environment and Natural Resources

Rural and north Rural and north
Geographic coverage: Ontario
Last Validated Date: June 4, 2026
Update frequency: Monthly