Otoe County is a county in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 15,912. Its county seat is Nebraska City. The county was formed in 1854, and was named tor the Otoe Indian tribe.

Fremont County is a county located in the U.S. state of Iowa. As of the 2020 census the population was 6,605, making it the state's seventh-least populous county. The county seat is Sidney. The county was formed in 1847 and named for the military officer John C. Frémont.