[2] Part of the Cheyenne-Arapaho land opening in 1892, the county had gained rail lines by the early 1900s and highways by the 1930s.

[3][4] The county was named for James G. Blaine, an American politician who was the Republican presidential candidate in 1884 and Secretary of State under President Benjamin Harrison.

When the time came to choose another name for the county, there seemed to be roughly equal support for two military heroes: "Sheridan" and "Custer".

Before voting began, the chair gave a stirring speech proposing Blaine, who had recently died and was a local favorite.

[3] The Cheyenne and Arapaho tribes were relocated to the area from Colorado in 1869 after the Reconstruction Treaties of 1866 had taken the land back from the Creek and Seminole.

[7] A post office was established in the county seat of Watonga, the same year as the land run.

[8] The town of Geary, which also received a post office in the same year as the land run, became an agricultural trade center in the county and had a population of 2,561 by 1902.

"[9] Okeene was also established in the year of the land run and was surrounded by farmers of German descent.

[3] New Deal programs such as the Civilian Conservation Corps employed county residents and built Roman Nose State Park, which opened in 1937.

[5] Lying in the Cimarron Valley, Okeene's economy has been based on agriculture, primarily wheat and hay.

[10] The Okeene Municipal Hospital and Clinic is one of the primary medical centers of northwest Oklahoma.

[10] School districts include:[24] The following sites in Blaine County are listed on the National Register of Historic Places: