Reynolds scored from 3 yards out in the first quarter and then scooped up a loose ball and galloped 70 yards for his second score of the day in the second quarter to put the Beavers (7-6) ahead 24-6.
Sean Mannion completed 24-of-33 passes for 259 yards for Oregon State, including a touchdown pass to Brandin Cooks. Storm Woods and Terron Ward ran for scores.
Boise State (8-5) took the field under interim head Coach Bob Gregory after longtime head Coach Chris Peterson accepted the head coaching job at Washington. The Broncos also were without starting quarterback Joe Southwick, who did not play after violating team rules.
Grant Hedrick started for the Broncos and completed 32-of-44 passes for 382, but did not put a touchdown on the board until Jay Ajayi ran a TD in from 1 yard out with 4:32 left in the third quarter.
Ajayi finished with 97 yards. Matt Miller caught 11 passes for 206 yards, including an 85-yard TD reception in the fourth quarter.