Montana (8-1, 4-1) took advantage of early turnovers to take a 28-0 lead on a 9-yard scoring pass from Bergquist to Mike Ferriter just three minutes into the second quarter.
The teams traded field goals before Reynolds scored on a 67-yard run with 9:07 left in the third to give the Grizzlies a 38-3 lead.
Ferriter had four catches for 56 yards and two touchdowns while Marc Mariani had three catches for 60 yards and a score.
The Grizzlies, ranked sixth in the Sports Network Poll, rushed for 223 yards against No. 19 NAU (6-3, 4-2) which had been allowing its opponents less than 19 yards rushing per game.
Deonte Williams rushed for 105 yards and a touchdown for the Lumberjacks.