Taylor Wood was mowing the pasture behind the family home on Sunday and heard a thud. He then saw a canister that said "TNT shell" on the side.
His mother, Charise Wood, describes the canister as looking like a small can of tomato paste. She quickly called emergency crews.
Charise Wood says the family has lived in the home seven years but had never mowed that area of pasture because they had let horses eat down the grass. Now the family has goats that aren't interested in that area.
The Weber County sheriff's department took the canister for disposal.
Hooper is about 35 miles north of Salt Lake City.