Arkansas inmate Larry D. Hulsey brought a 42 U.S.C. § 1983 action raising various constitutional and state-law claims arising from an alleged beating by certain defendants. Before entertaining defendants’ motions based on the failure to exhaust administrative remedies, the Magistrate Judge conducted an evidentiary hearing to determine whether such remedies had been available to Hulsey. After the hearing, the Magistrate Judge recommended dismissal, citing numerous reasons for discrediting Hulsey’s testimony about why he had been effectively prevented from complying with the prison grievance procedure. The District Court 1 conducted de novo review and adopted the Magistrate Judge’s report in its entirety. Hulsey appeals.

Having reviewed the District Court’s conclusions of law de novo and its findings of fact for clear error, see Choate v. Lockhart, 7 F.3d 1370, 1373 & n. 1 (8th Cir. 1993), we affirm the dismissal, see 42 U.S.C. § 1997e(a) (2000) (stating no § 1983 action shall be brought by inmate with respect to prison conditions until such administrative remedies as are available are exhausted); United States v. Womack, 191 F.3d 879, 885 (8th Cir. 1999) (observing that a district court’s credibility determination is “virtually unreviewable” on appeal (citations and internal quotation omitted)).

Accordingly, we affirm the judgment of the District Court.