The population of Cass Lake is comprised of many ethnic groups, and a majority of its residents are American Indian. However, the town is also home to significant numbers of people with other ancestry. Approximately 66.8% of the population is American Indian, while the other twenty percent is white. The city is within the Leech Lake Indian Reservation. The median age of its population is 31.8 years.
Crime statistics in Cass Lake show that the rate of violent crime per thousand residents is 5.43. The city's southeast is considered one of the safest parts, with the risk of being the victim of a violent crime being as low as one in three25 in the east part of town. Comparing these two crime rates is not as straightforward as one might assume. Crimes occur wherever people gather, and Cass Lake is no different.
The area was inhabited by successive cultures of indigenous people. Among them were the Ojibwe and Chippewa, who moved across present-day Minnesota. In December 1898, a post office was established in the town. The postmaster of the town named it Tuller after his brother-in-law. It was renamed Cass Lake in March 1899.
The federal government has long been a major employer in the community. In 1902, the Minnesota Forest Reserve chose Cass Lake as the location of its Forest Supervisor's Office. The Civilian Conservation Corps was responsible for the management of over a dozen camps. In 1936, the Civilian Conservation Corps completed the magnificent log-construction Forest Supervisor's Office. In addition, the Civilian Conservation Corps also founded the Lydick Nursery, which produced millions of seedlings for reforestation work.