COE rules: http://www.access.gpo.gov/nara/cfr/waisidx_02/36cfr327_02.html

CFR title-36 327.13 says:

(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 Sec. 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.

Section 327.8 says:

Sec. 327.8 Hunting, fishing, and trapping.

(a) Hunting is permitted except in areas and during
periods where prohibited by the District Commander.
(b) Trapping is permitted except in areas and during
periods where prohibited by the District Commander.
(c) Fishing is permitted except in swimming areas, on
boat ramps or other areas designated by the District
Commander.
(d) Additional restrictions pertaining to these
activities may be established by the District Commander.
(e) All applicable Federal, State and local laws
regulating these activities apply on project lands and waters, and shall be
regulated by authorized enforcement officials as prescribed in Sec.
327.26.



Simply, bows and arrows are allowed when used for fishing as long as it's a fishing area. (at least that's how it appears to me from their rules) [:-]