Hidalgo County is the boot heel of New Mexico, in the southwest corner of the state with Arizona to the west and Mexico to the south. Some stories say Hidalgo County was named in honor of Miguel Hidalgo, while other sources say the county was named in honor of the Treaty of Guadalupe Hidalgo, although that treaty left the area as part of Mexico and it was the Gadsden Purchase 5 years later that incorporated Hidalgo County into the United States.

Formed in 1919, Hidalgo County contains 3,446 square miles of land and about 1/3 of a square mile of water. The county seat is Lordsburg.