The sign, which was posted on private property across from Fairhaven Middle School, warns "semi-literate thieves" that four different types of guns are on site four days a week.
Some parents and residents in the area say having a sign that hints at gun violence so close to young children sends the wrong message. One resident says she noticed the sign go up the same week as the Sandy Hook school shooting in Connecticut.
"We were already crying because of all of the children that had lost their lives and the teachers," said Pat Briggs-Yazzie, "(and then we) noticed the sign. Just infuriated me that somebody would be threatening to shoot people across from our middle school."
"I think it's terrible. I think there's too many guns in this country and it's too violent," added Paul Hammond, who is originally from the United Kingdom. "To me, yes, people kill, but if they didn't have the guns they couldn't use them to kill and guns near schools. It's wrong."
Despite those complaints, police say the sign is completely legal. Officers also say they were called the property back in December after $400 worth of scrap metal and materials was stolen from the site.
"It's a no trespassing sign. It's posted on private property. There are no threats being made on the sign," said Mark Young of the Bellingham Police Department. "It's a legal sign on private property that does not violate any laws that I'm aware of."
The landowner who posted the sign didn't want to comment on it, but some in the area say they understand Second Amendment rights can be displayed in a First Amendment way.
"I work in the construction industry and I know about getting break-ins on job sites, and it's frustrating," said Jeralyn Conrad, whose son is a 6th grade student at Fairhaven Middle School. "I don't have a problem with the sign at all. If I found out he was carrying an arsenal there across the street, then I might have a problem with it."
A Bellingham School District official said the property owner has talked with a school leader, but has no plans to remove the sign.
"We do not support this advertisement of weapons," added district spokeswoman Tanya Rowe in a statement, "but the sign is not on our property and we have no authority on the issue."