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United States Department of Transportation United 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) December 25, 2023 February 18, 2024 February 20, 2024
DOF (Zip) February 19, 2024 April 14, 2024 April 16, 2024
DOF (Next) April 15, 2024 June 09, 2024 June 11, 2024

DOF Frequently Asked Questions (FAQ)

For additional information read DOF ReadMe (PDF)

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