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Digital Obstacle File (DOF)

The Digital Obstacle File (updated every 56 days) describes all known obstacles of interest to aviation users in the United States, with limited coverage of the Pacific, the Caribbean, Canada, and Mexico. The obstacles are assigned unique numerical identifiers; accuracy codes, and listed in order by state.

To download a file, right-click, then select "Save" / "Save As" / "Save Target As" to save the desired file to your computer. If you download a zipped file, use an unzip utility to extract the files. The DOF is a .dat file, so you may use Wordpad or most browsers to access it. If you prefer Notepad, use the Courier font to retain proper column formatting.

New - Please note that all normal release dates have recently been changed from Mondays to Tuesdays.

Digital Obstacle Files
Product Reflects Changes From Reflects Changes To Release Date
DOF (Zip) March 22, 2021 May 16, 2021 May 18, 2021
DOF (Zip) May 17, 2021 July 11, 2021 July 13, 2021
DOF (Next) July 12, 2021 September 05, 2021 September 07, 2021

DOF Frequently Asked Questions (FAQ)

For additional information read DOF ReadMe (PDF)

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