Originally a part of the Louisiana Purchase in 1803, Carter County was created in February, 1917 from land belonging to Fallon County. Named in Honor of U.S. Senator, Thomas Henry Carter, the territorial delegate to Washington, D.C. prior to Montana becoming a state in 1889.

As the Montana Territory was settled, communities like Alzada (Stoneville) sprang up in the southeast corner of Carter County with Hammond, Ridgeway, Belltower & Mill Iron appearing along Box Elder Creek and Albion and Capitol along the Little Missouri River.

Ekalaka, the county seat, was named in honor of Ijkalaka, daughter of Eagle Man, an Oglala Sioux and the wife of David H. Russell, the first white settler in the picturesque Russell Creek Valley. She was a niece of the War Chief Red Cloud, and was also related to Sitting Bull. The spelling was changed in 1885, when the post office was established.

Ekalaka was once known as the biggest inland town in the nation not served by a railroad. It is still 36 miles from the nearest rails.

Ekalaka is known as the “Bucking Horse Capital of the World”. The territory around Ekalaka has brought forth more world champion class bucking horses than any other town or area has produced. Bucking horses that have grown up in the Powder River Breaks, west of Ekalaka, have won the NFR Best Saddle Bronc award a record of six times. This bloodline has produced in excess of 2500 bucking horses.