The sheep was found dead from apparent head trauma.
15-year-old Maddie Moore found her sheep named Rocket Chocolate dead, and says the rest of her sheep had been terrorized at their Vancouver home.
Moore's father found fireworks in their pen, and many of their food stations knocked over.
Maddie saved $250 to buy the sheep and was raising it to take to the county fair.
Clark County law enforcement and animal control officials say they don't have the resources to investigate unless they have more evidence.