The International Institute of Minnesota created the Festival of Nations in 1936 to celebrate the ethnicities and cultures of people living in Minnesota. Since then, the event has grown to reflect the increasing diversity of the state.

Huset School, an example of the kind of one-room log schools once common in northern Minnesota, was built in Boy Lake Township (Cass County) in 1912. Cass County Historical Society restored it in 1968 and opened it to the public as a historic site.

The International Institute in St. Paul opened on December 12, 1919. For one hundred years, it has helped meet the needs of immigrants, refugees, and asylees beginning their new lives in Minnesota.

The sixth and final dam in the Headwaters Reservoir System, Gull Lake Dam was built in 1912 to increase the output of mills and turbines downstream. In 2019, the dam maintains water levels for recreation and navigation, and the site is also home to ancient burial mounds and a recreation area.

On April 24, 1926, Herbert W. Sellner filed an application with the United States Patent Office for an “Amusement Device” designed for parks and resorts. His goal was to provide riders with “pleasurable and unexpected sensations” by swinging, snapping, and rotating them in an unpredictable pattern. He named his creation the Tilt-A-Whirl, and it became the most popular ride made by his Faribault-based Sellner Manufacturing Company.

The 1918 influenza epidemic had a devastating effect on communities across Minnesota, including those in Cottonwood County. Over the course of five months (October 1918–February 1919), seventy-two residents of the county died from the virus or from pneumonia-related complications.

Francis Lee Jaques emerged from rural Minnesota in the 1930s and 40s to become a nationally known wildlife artist. After two decades at the American Museum of Natural History in New York, he returned to his home state to paint a much-loved series of habitat dioramas at the University of Minnesota’s Bell Museum. His images of Minnesota are a valuable record of the state’s natural history.

On the night of May 6, 1965, two F4 tornadoes cut through the northwest Twin Cities metro area. Known collectively as the Fridley tornado, these twisters were the worst cyclonic disaster to hit the Twin Cities to date.

Cottonwood County’s now-dry Mountain Lake was the site of Indigenous villages and encampments over the course of 3,000 years. The area has provided clues—some of the oldest evidence of human habitation in present-day Minnesota—about the lives of a group of people who remained relatively isolated from Upper Mississippi trade networks. In the 1970s, the site was developed into a public park operated by Cottonwood County.

The Ranier Railroad Bridge (Canadian National River Bridge) was constructed in 1908 by the Canadian Northern Railway and its subsidiary, the Duluth, Rainy Lake and Winnipeg Railway. The single-track lift bridge crosses Rainy River between Ranier, Minnesota, and Fort Frances, Ontario, and is one of the busiest ports of entry for international rail freight in the United States.