i thought it was 18 on bases that were within 50 miles of the border
***The minimum drinking age on a DoD installation located in a State (including the District of Columbia) shall be consistent with the age established by the law of that State as the State minimum drinking age. Minimum drinking age means the minimum age established for persons who may purchase, possess, or consume alcoholic beverages.
In the case of a DoD installation located in more than one State or in one State but within 50 miles of another State or Mexico or Canada, the minimum drinking age on that DoD installation shall be the lowest applicable age of the State in which the DoD installation is located or the State or jurisdiction of Mexico or Canada that is within 50 miles of such DoD installation.
The minimum drinking age on a DoD installation located outside the United States shall be 18 years of age. Higher minimum drinking age will be based on international treaties and agreements and on the local situation as determined by the local installation commander.
The commander of a DoD installation may waive the above requirements, if such commander determines that the exemption is justified by special circumstances. Special circumstances are those infrequent, non-routine military occasions when an entire unit, as a group, marks at a military installation a uniquely military occasion such as the conclusion of arduous military duty or the anniversary of the establishment of a military service or organization. The event must be held on a military installation. The commander shall ensure that appropriate controls are in place to prevent endangering Military Service members or the surrounding community.