Northeastern State University (NSU) is a public university with its main campus in Tahlequah, Oklahoma, United States, at the foot of the Ozark Mountains. Tahlequah is also home to the capital of the Cherokee nation of Oklahoma. The university also has two other campuses in Muskogee and Broken Arrow. Northeastern is the oldest institution of higher learning in the state of Oklahoma as well as one of the oldest institutions of higher learning west of the Mississippi River.