During construction of the Eastman tunnel in St. Anthony, Minnesota (now Minneapolis), the Mississippi River broke through the tunnel's limestone ceiling, nearly destroying Saint Anthony Falls.

The Eastman tunnel, also called the Hennepin Island tunnel, was a 2,000-foot-long (600 m) underground passage in Saint Anthony, Minnesota, 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.

Minneapolis is a city in Hennepin County, Minnesota, United States, and its county seat. With a population of 429,954 as of the 2020 census, it is the state's most populous city. Located in the state's center near the eastern border, it occupies both banks of the Upper Mississippi River and adjoins Saint Paul, the state capital of Minnesota. Minneapolis, Saint Paul, and the surrounding area are collectively known as the Twin Cities, a metropolitan area with 3.69 million residents. Minneapolis is built on an artesian aquifer on flat terrain and is known for cold, snowy winters and hot, humid summers. Nicknamed the "City of Lakes", Minneapolis is abundant in water, with thirteen lakes, wetlands, the Mississippi River, creeks, and waterfalls. The city's public park system is connected by the Grand Rounds National Scenic Byway.

The Mississippi River is the primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for 2,340 mi (3,770 km) to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. The main stem is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km²), of which only about one percent is in Canada. The Mississippi ranks as the world's tenth-largest river by discharge flow, and the largest in North America.