Toby Young Bear directly appeals the sentence of 4 months in prison imposed by *659 the district court 1 upon revoking his supervised release. Because Young Bear has been released from custody and has fully discharged his revocation sentence, we dismiss this appeal as moot. Cf. Spencer v. Kemna, 523 U.S. 1, 7-18, 118 S.Ct. 978, 140 L.Ed.2d 48 (1998) (declaring challenge to allegedly erroneous parole revocation moot because defendant had already served his entire sentence). We also deny counsel’s motion to withdraw as moot.