Angelo Gonzales, Louisiana prisoner # 114052, appeals the dismissal of his 42 U.S.C. § 1983 complaint, in which he sought relief arising out of incidents on July 17, 18, and 19, 2006. We review the dismissal of a complaint on the pleadings de novo, employing the same standard applied to dismissals for failure to state a claim under Fed. R. Civ. P. 12(b)(6). Johnson v. Johnson, 385 F.3d 503, 529 (5th Cir. 2004). Finding no error, we affirm.

The Prison Litigation Reform Act requires prisoners to exhaust administrative remedies prior to filing a § 1983 complaint challenging prison conditions. 42 U.S.C. § 1997e(a); Woodford v. Ngo, 548 U.S. 81, 88-89, 126 S.Ct. 2378, 165 L.Ed.2d 368 (2006). Gonzales was required to file a grievance within ninety days of the alleged incidents. La. Admin. Code tit. 22 § 325(A)(2) (2008); Johnson v. La. ex. rel. La. Dept. of Pub. Safety & Corr., 468 F.3d 278, 280 (5th Cir. 2006) (per curiam). According to Gonzales’s own pleadings, including the complaint that he signed under penalty of perjury, the earliest date that he submitted a grievance was October 18, 2006, the ninety-first day after the July 19 incident.

Gonzales argues that he was prevented from timely filing because he was denied access to writing materials. Gonzales did not raise this argument in the district court, and we need not consider it here. See Leverette v. Louisville Ladder Co., 183 F.3d 339, 342 (5th Cir. 1999) (per curiam). Further, Gonzales’s argument is conclusory and unsupported by any citations to evidence in the record. In sum, the dismissal of Gonzales’s complaint for failure to exhaust administrative remedies was not erroneous. Accordingly, we need not *299 reach the determination that the Louisiana Department of Public Safety and Corrections is immune from suit under the Eleventh Amendment, although that determination is supported by our precedent. See Champagne v. Jefferson Parish Sheriffs Office, 188 F.3d 312, 313-14 (5th Cir. 1999) (per curiam).

Finally, Gonzales has filed a motion for summary judgment in this court. He must file any such motion in the district court.

The judgment is AFFIRMED. The motion for summary judgment is DENIED.