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United States Department of TransportationUnited States Department of Transportation

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) August 08, 2022 October 02, 2022 October 04, 2022
DOF (Zip) October 03, 2022 November 27, 2022 November 29, 2022
DOF (Next) November 28, 2022 January 22, 2023 January 24, 2023

DOF Frequently Asked Questions (FAQ)

For additional information read DOF ReadMe (PDF)

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