Falk transferred from Logan, Utah to Westlake, California to play at famed Christian Oaks High School. He didn't quite fit in, however, so he moved back to Logan and had a first-team All-State senior season. He redshirted in his first year in Pullman as a walk-on, but got on the field in 2014, playing in six games and starting three (64.2 percent completion, 1,859 yards, 13 touchdowns, seven interceptions). Falk ran Mike Leach's system to a tee in 2015, earning first-team All-Pac-12 honors after ranking second in FBS by completing 69.4 percent of his passes for a nation-leading 380.5 yards a game (38 touchdowns, eight interceptions). The three-time finalist (and 2017 winner) for the Brandon Burlsworth Trophy award as the nation's top former walk-on played well again in a second-team All-Conference 2016 season (343.7 yards/game--ranked fourth in the country, 70.0 completion percentage-second, 38 touchdowns, 11 interceptions). Falk's accuracy, mobility within the pocket, and smart decisions make him a finalist for the Manning and Johnny Unitas Golden Arm Awards. Falk's senior season did not quite go as planned, as he was benched at times and only managed to receive honorable mention All-Conference honors. He still completed 66.9 percent of his passes (357 completions, 534 attempts) for 3,593 yards, 30 touchdowns, and 13 interceptions in 13 starts. Falk did set several Pac-12 career records, including total offense, passing touchdowns, passing yards, completions, and attempts.