Van Pelt had runs of 31, 19, 36 and 27 yards -- two of them on scrambles -- to help Colorado State (3-3) score on five straight possessions and snap a two-game losing streak.
Marcus Houston, who had a critical fumble in the closing minutes last week of a 28-21 loss to Utah, ran for two touchdowns and caught one of Van Pelt's TD throws.
Van Pelt's 31-yard scramble set up his 7-yard scoring pass to David Anderson late in the first half, capping a 96-yard drive and giving the Rams a 10-3 lead.
Van Pelt had a 19-yard run and a 14-yard scramble on the Rams' first series of the third quarter, setting up his 5-yard TD throw to Houston.
He scrambled 36 yards on the next series prior to Houston's 2-yard scoring run for a 24-3 lead.
After Berrian's score, Colorado State's Jeff Babcock kicked a 39-yard field goal.
Early in the fourth quarter, Van Pelt bolted for 27 yards. Three plays later, Houston scored on a 3-yard run.
The Bulldogs' other score came in the first quarter after safety James Sanders rushed Van Pelt, tipped a pass and intercepted at the CSU 18. Four plays later, Brett Visintainer kicked a 27-yard field goal.
Fresno's Paul Pinegar replaced starting quarterback Jeff Grady late in the first half. It was the first appearance of the season for Pinegar, the Western Athletic Conference's freshman of the year in 2002 who tore his right pectoral muscle on Aug. 20.