KMSR (1520 AM) is a radio station in Mayville, North Dakota, serving the Red River Valley of eastern North Dakota and northwest Minnesota with ESPN Radio. KMSR is known as "Your Sports Leader in the Red River Valley" in reference of their coverage of local high school sport events. KMSR is on the air in the daytime only, so it signs off at sunset, and signs on again at sunrise.
KMSR airs NBC Sports Radio, occasionally preempted by local sports coverage. KMAV covers the Red River Valley area, including Mayville, Grand Forks, and Fargo. Simulcast for many years, KMAV-FM and KMSR (formerly KMAV) have been broadcasting separate programming since November 2003.
KMSR is family owned. Five-time North Dakota Sportscaster of the Year, Dan Keating, calls basketball, baseball, football, volleyball, and wrestling. His wife, Mary, is the company's president. Their children are also active in the company.