The Corps allows hunting on some of its land. Except for hunting, possession of a functional firearm is prohibited on Corps land — even a handgun inside one’s own tent. In Nesbitt v. U.S. Army Corps of Engineers, the Mountain States Legal Foundation (a public-interest law firm based in Denver) filed a lawsuit on behalf of two Idaho residents, regarding Corps recreational land in Idaho. In 2014, Federal District Judge B. Lynn Winmill (appointed in 1995 by President Bill Clinton) ruled that the ban violates the Second Amendment. The Obama administration then appealed the ruling to the U.S. Court of Appeals for the 9th Circuit.
The prohibition was adopted in 1973, during the Richard Nixon administration. Nixon – -the only U.S. president ever to resign in order to avoid certain removal from office by the House and Senate — thought “guns are an abomination.” His administration promulgated a variety of anti-gun regulations. The regulation in question states:
(a) The possession of loaded firearms, ammunition, loaded projectile firing devices, bows and arrows, crossbows, or other weapons is prohibited unless: (1) In the possession of a Federal, state or local law enforcement officer; (2) Being used for hunting or fishing as permitted under § 327.8, with devices being unloaded when transported to, from or between hunting and fishing sites; (3) Being used at authorized shooting ranges; or (4) Written permission has been received from the District Commander. (b) Possession of explosives or explosive devices of any kind, including fireworks or other pyrotechnics, is prohibited unless written permission has been received from the District Commander.
36 C.F.R. § 327.13. Note that by banning ammunition, the regulation also forbids the possession of unloaded firearms that could be loaded in an emergency (if sufficient time were available).