25 CFR § 11.804 - Briefs and memoranda.
(a) Within 30 days after the notice of appeal is filed, the appellant may file a written brief in support of his or her appeal. An original and one copy for each appellee shall be filed with the clerk of court who shall mail one copy by registered or certified mail to each appellee.
(b) The appellee shall have 30 days after receipt of the appellant's brief within which to file an answer brief. An original and one copy for each appellant shall be filed with the clerk of the court who shall mail one copy, by registered or certified mail, to each appellant.