[1] In July 1999 he participated in the ABCD Camp for the best high school players in the nation,[9] averaging 9.8 points, 3.4 rebounds and 0.6 assists per game during the event.
[13] He ended his senior season earning District MVP[5] and All-State first team honors,[5][14] averaging 24 points, 8 rebounds and 2.5 blocks per game.
[1][2] He was also named MVP of the Louisiana High School Coaches Association All-Star Game played on July 23, 2000, during which he scored 24 points.
[8] Mouton was recruited by several NCAA Division I schools: he had visits with Louisiana-Lafayette, LSU, Purdue, Southern Miss and Texas, and received interest from top programs such as Kansas, Kentucky, Michigan, Syracuse and UConn.
[10][17] Mouton chose to wear jersey number 3 and in his freshman year he was primarily used as Maurice Evans' backup in the small forward position.
[20] Mouton's sophomore season saw him earning a starting role in the rotation, after Evans declared for the 2001 NBA draft.
[2] He ended the season with averages of 13.7 points (2nd on the team behind Chris Owens), 4.6 rebounds and 1.3 assists per game while shooting 39.4% from three (which at the time was the 7th best single-season performance in Longhorns history).
[23] For his junior year Mouton was confirmed in the starting five by coach Rick Barnes, and in the first five games of the season he scored at least 10 points.
[26] In the NCAA Sweet Sixteen game against UConn Mouton recorded a career-high 27 points while shooting 4/7 (57.1%) from three-point range.
[28] Mouton was one of the players who joined the Texas Longhorns in 2000 and decided to return to the team for their senior season: with him, Brian Boddicker, Royal Ivey and James Thomas, who were all part of the rotation during the previous year participation in the Final Four.
Mouton scored 20 points on November 24, 2003, against Sam Houston State, and on December 4 against Wofford; he did not play on January 2 against UT Arlington, missing the first game of his career at Texas after 109 consecutive appearances.
[2] During the Big 12 tournament Mouton averaged 13.3 points and 4.3 rebounds (including an 18-points performance against Kansas), and earned All-Tournament honors.