Neighbors are now ready to take legal action to stop it.
"It literally sounds like you're in the middle of a war zone," said Robert Nissenbaum, who lives in the rural neighborhood in the outskirts of the city of Sebastopol.
"Loud bursts. Explosions of noise. If it started, you would be shocked," another neighbor, Kim Roberts, told ABC7 News.
Neighbors say this gunfire, which was first reported by The Press Democrat, started about two months ago and can be heard for miles. It sometimes goes on for hours and is terrifying to the many people - and pets - who hear it.
"There's one Korean War veteran who lives very close, and he's described it as having PTSD symptoms," Nissenbaum said. "And every time there's a shot, it triggers that he's back in the middle of a war."
Tom Danaher, another neighbor, said many parents have been sharing their concerns on Nextdoor.
"One mom said I had to convince my kids that someone wasn't coming to shoot them. That was the quote," Danaher said.
"A lot of people responded that their animals were in distress," he added.
Danaher has been recording videos from his property of the loud explosions. In them, you can hear a neighbor firing off rounds and rounds ammunition. He said whenever the gunfire starts it's especially challenging for his 90-year-old mother-in-law.
"I'm not anti-gun," Danaher said. "I'm all for responsible gun ownership, but this doesn't meet our definition as a family, as a husband as a son-in-law."
He and a group of neighbors have reached out to the Sonoma County Sheriff's Department and their county supervisor for help, but county officials have told them since the man is on private property it's out of their hands.
Neighbors feel strongly what the homeowner is doing is illegal. They have hired an attorney to pursue legal action.
"We have two local ordinances here where we believe a plain reading of them we have a clear violation," Pamela Stevens, the attorney representing the neighbors, told ABC7 News.
One of the ordinances says a firearm cannot be used within 150 yards of a residence or an area where people frequent and assemble. Neighbors say he does not keep that distance from their properties.
"You hear this gunfire and you can't see where they're shooting," Roberts said. "You don't know if you're safe, and so you're assuming that you're not since the weapons he's using, the bullets, can travel for a mile or more."
The homeowner in question did not return ABC7 News' request for comment.
A Sonoma County official deferred us to the Sonoma County Sheriff's Department.
A spokesperson for the Sheriff's Department sent us a brief statement saying "the shooting range is a non-law enforcement issue, and more of a civil dispute."
Neighbors disagree and say it may be time for a judge to decide.
"Read the ordinance," Nissenbaum said, "And enforce it."