COUNTY ORGANIZED: 1889

COUNTY NAMED FOR: Robert Anderson Irion, a physician, surveyor, and Republic of Texas secretary of state.

COUNTY SEATS: Two - Sherwood and Mertzon.

COUNTY SEAT NAMED FOR: M. L. Mertz, a San Angelo banker who was also a director of the Kansas City, Mexico and Orient Railway.

COURTHOUSES: Two - Sherwood in 1901 and Mertzon in 1937.

STANDING: Two -

• 1901 Second Empire courthouse built of limestone in Sherwood.  Now serves as a community center.
• 1937 Modern courthouse built of brick in Mertzon.