Eastman tunnel

Eastman tunnel - Credit: Wikimedia Commons

The Eastman tunnel, also called the Hennepin Island tunnel, was a underground passage in Saint Anthony, Minnesota, (now Minneapolis) dug beneath the Mississippi River riverbed between 1868 and 1869 to create a tailrace so water-powered business could be located upstream of Saint Anthony Falls on Nicollet Island. The tunnel ran downstream from Nicollet Island, beneath Hennepin Island, and exited below Saint Anthony Falls. Read more on Wikipedia

type: NRHP
date from: 1868

Source: en.wikipedia.org