Americans across the country are digging up a dangerous and potentially deadly series of finds in their very own backyards.

Carl Granberry found an entire ammunition cache — belts and belts of vintage World War II machine gun rounds — and expects to dig up a bomb or a grenade any day now. 

"I spent two tours in Vietnam," he said. "I was shot at by experts. I'm not afraid of being shot by a lone hand grenade."

Granberry's land is situated on the 14,000 acres that used to be Camp Fannin, where some 250,000 soldiers trained with live fire before being shipped off to war.

After the camp was shut down in 1946, the land was left vacant, so no one bothered to clean it up.

In fact, it is estimated that on some 9,000 old military training sites across the U.S., old bombs and hand grenades were left in the ground.

Today, as cities expand and homes go up on the old firing ranges, everything from bombs to bazooka rounds are turning up.

It is now up to an Army Corps of engineers, backed by a billion dollar budget, to clean up the old artillery sites.

"We found 155-mm high explosive rounds. They hold about 15-pounds of explosives," Brian Clondike, a U.S. Army Corps engineer, said.

"We've had hand grenades, land mines, plus a lot of small arms, rifles, pistols, machine gun bullets," he said.

The clean-up project could take years, but needs to be seen through to the end because old bombs can and do go off.

"There was a brush fire near mineral wells grounds of the former Camp Walters. They had one or more rounds explode because the fire set them off," Clondike said. "So it can happen, and it's dangerous."

Despite the danger, Granberry is honored to own property with some World War II history attached to it.

"It's humbling, really, to think that the training that went on here helped save the world," he said.

Michael Tobin joined FOX News Channel (FNC) in 2001 and currently serves as a Chicago-based correspondent.