There were many newspaper mentions of tunnels built by Chinese laborers in the late 1800s. They weren’t in Boise, though. The stories that mentioned the tunnels were about mining in the mountains.
Boise had a substantial Chinese population in the late 1800s and early 1900s, but did they build tunnels? If they didn’t, where did the myth come from? There were Chinese tunnels, most famously in San Francisco. Portland had a network called the Shanghai tunnels. Los Angeles had Chinese tunnels. Did Boise?
I searched for mention of them in digital scans of the Statesman from those years and turned up nothing. The first mention I found of Chinese tunnels in the Statesman was in a column by Dick d’Easum in 1961. He was addressing the “myth” of the tunnels and speculating on how it got started. There were underground rooms that led off basements in the Chinese section of the city. It was said that illicit activities sometimes occurred there, such as the smoking of opium. What did not seem to be the case was that those rooms connected in a network beneath the city that would allow someone to enter at one point and pop up blocks away.
One possible source of the tunnel stories was the prevalence of unauthorized sewers. Today we hear of sinkholes opening up and swallowing cars. In Boise in the 1880s such sinkholes could make horses disappear. Dick d’Easum told of a wagon loaded with merchandise that suddenly sank half out of sight on Idaho Street. The struggling team of horses were soon pulled into the widening hole. A Chinese sewer was the cause. Once the team and wagon were extricated it was filled in. The city engineer found more unauthorized sewers and the city council decreed that they all be filled in.
Over the years Boise has had countless street and utility projects, not to mention the construction, deconstruction, and reconstruction of numerous buildings. No Chinese tunnels have been found. Yet, the myth persists. That’s partly because one can’t prove a negative such as this. There MIGHT be a system of tunnels somewhere that have yet to be found. Dig deeper, maybe. Great Uncle Hyrum said he saw them.
By the way, the graphic is supposed to be “China Tunnel” in pinyin, if you can trust those internet translation services.