The Cowboys held Mississippi Valley to 33 percent shooting and forced 23 turnovers. Oklahoma State owned a massive 63-29 halftime lead and eventually put five players in double figures.
Le'Bryan Nash added 21 points for the Cowboys in their season opener with both Markel Brown and Brian Williams contributing 14.
Mississippi Valley was led by DeAngelo Priar with 17 points.
Oklahoma State shot 59 percent from the field and made 12-of-21 from 3-point range.