Accepting a scholarship to
Fresno State, Rivers played in all but one of the team's 14 games, including seven starts. As a true freshman, Rivers ran for 480 yards on 101 carries and scored five touchdowns while also catching 20 passes for 129 yards and a TD in
2017, with his best game coming in a 27–10 victory over
San Jose State, in which he ran for 105 yards on 19 carries and two touchdowns. Against
Wyoming, Rivers scored the first receiving touchdown of his college career on 21-yard reception in the second quarter, which proved to be the Bulldogs' only TD in a 13–7 victory that clinched a berth in the
Mountain West Conference championship game. He was also named Mountain West scholar-athlete. In his sophomore season, Rivers appeared in 11 games and made six starts and totaled 1,192 all-purpose yards and scored a team-high 13 touchdowns. He was the Bulldogs' leading rusher with 743 yards on 132 carries and 10 rushing touchdowns while also recording 26 receptions for 311 yards and three receiving touchdowns. He also led
Fresno State in punt returns with 14 for 138 yards. Against
New Mexico, Rivers scored a career-high three touchdowns (two rushing, one receiving) in Fresno State's 38–7 win. Other season highlights included 125 yards on 11 carries, including a 76-yard run against
Hawaii and scoring the game-winning TD in overtime against
Boise State in the Mountain West Conference Championship Game. Rivers was named MVP of the
Las Vegas Bowl after setting single-game career highs in rushing attempts (24) and yards (212) while also having a 41-yard punt return as the Bulldogs defeated
Arizona State 31–20. Rivers started all 12 games as a junior in
2019, leading the Bulldogs in rushing with 899 yards and 13 touchdowns along with 348 yards and three touchdowns receiving to earn second team All-Mountain West Conference honors. He had four 100-yard rushing games including three straight against
Colorado State (146 yards, two touchdowns), at
Hawaii (103 yards, two touchdowns), and
Utah State (102 yards, three touchdowns). In Fresno State's season-ending 17–16 loss to
San Jose State, Rivers had a season-high 177 yards on 29 carries and a touchdown and caught eight passes for 63 yards. As a senior, Rivers started five of
Fresno State's six games and started five during the Bulldogs' 3–3 season which was abbreviated due to the
COVID-19 pandemic. Rivers ran for 507 yards on 100 carries with seven touchdowns on the ground and 27 receptions for 265 yards and two touchdowns receiving. He was named Mountain West Conference Player of the Week against
UNLV after totaling 19 carries for 133 yards and three touchdowns and catching six passes for 99 yards and one more touchdown in the Bulldogs' 40–27 victory. The following week, Rivers ran 25 times for 132 yards and a TD and added six receptions for 51 yards as Fresno State beat
Utah State 35–16. Rivers was named first team All-Mountain West running back following the season. Granted an extra year of eligibility following the pandemic, Rivers returned for a fifth season and was a Bulldogs team captain for
2021. Rivers had a season-best 136 yards rushing and two touchdowns on 21 carries at then-No. 13
UCLA, leading Fresno State to a 40–37 upset of the Bruins. In a 40–9 rout of
San Jose State, Rivers had a season-high 169 all-purpose yards, finishing with 65 yards rushing and 91 yards receiving, while adding 13 kick return yards. Starting all 11 games on the season, Rivers was again named first team All-Mountain West Conference with 788 rushing yards on 162 attempts with five touchdowns and 34 receptions for 364 yards and two touchdowns receiving. Rivers finished his Bulldog career with team records in touchdowns scored (52), rushing touchdowns (40), receiving touchdowns by a running back (12), receiving yards by a running back (1,417) and pass receptions by a running back (150); was third in program history with 3,417 career rushing yards, second in career rushing attempts (672), and fourth in 5,208 career all-purpose yards.
Statistics == Professional career ==