Active installation refers to an installation in continuous use by active Army organizations.
The following is an example of federal law on military installation:
Military installation means any land or interest in land owned by the U.S. and administered by the Secretary of Defense or the Secretary of a military department, except land under the jurisdiction of the Assistant Secretary of the Army having responsibility for civil works. It includes all public lands withdrawn from all forms of appropriation under public land laws and reserved for use by the Secretary of Defense or the Secretary of a military department. [16 USCS § 670].