Amie Lynn Nieto seeks to appeal the district court’s order denying her 28 U.S.C. § 2255 (2000) motion. We dismiss the appeal for lack of jurisdiction, because the notice of appeal was not timely filed.

When the United States or its officer or agency is a party, the notice of appeal must be filed no more than sixty days after the entry of the district court’s final judgment or order, Fed. R.App. P. 4(a)(1)(B), unless the district court extends the appeal period under Fed. R.App. P. 4(a)(5) or reopens the appeal period under Fed. R.App. P. 4(a)(6). This appeal period is “mandatory and jurisdictional.” Browder v. Director, Dep’t of Corr., 434 U.S. 257, 264, 98 S.Ct. 556, 54 L.Ed.2d 521 (1978) (quoting United States v. Robinson, 361 U.S. 220, 229, 80 S.Ct. 282, 4 L.Ed.2d 259 (1960)).

The district court’s order was entered on the docket on January 20, 2004. We recently remanded this case in order for the district court to determine the date Nieto delivered her notice of appeal to prison officials for mailing to the court. See Fed. R.App. P. 4(c); Houston v. Lack, 487 U.S. 266, 108 S.Ct. 2379, 101 L.Ed.2d 245 (1988). The district court determined that Nieto filed her notice of appeal on April 12, and Nieto has not challenged that finding. Because the district court’s factu *777 al finding is not clearly erroneous and because Nieto failed to obtain an extension or reopening of the appeal period, we dismiss the appeal as untimely. We dispense with oral argument because the facts and legal contentions are adequately presented in the materials before the court and argument would not aid the decisional process.

DISMISSED