After a mining explosion in Livingston, Montana, dinosaurs believed to be extinct suddenly emerge from the rubble. Now, a disgraced cowboy, who recently returned home to make amends for past wrongdoings towards his ex-girlfriend, must team up with her new boyfriend—the sheriff—to defend their town against the rampaging beasts. With the help of a few local gunslingers, the posse must band together in order to survive the deadly attack and take back their town.