Alamogordo's County is Otero, a county located in the U.S. state of New Mexico. It is the second-largest county in the state, covering an area of 6, 628 square miles. The county seat is Alamogordo, which is also the largest city in the county. Otero County was established in 1899 and named after Miguel Antonio Otero, a prominent local politician. The county is home to several national parks and monuments, including White Sands National Monument and Lincoln National Forest.