New Mexico Highlands University is one of New Mexico's oldest colleges and was once the state's largest university. The Armand Hammer United World College of the American West is one of nine United World Colleges and the only one in the United States. Pecos Pueblo was once a major trade center on the eastern flank of the Puebloan world. In 1927, archaeologists came to Pecos and developed a classification system to help identify the cultural development of the Southwestern people. The system they came up with is still in use today.
Union County produces twice as many cattle than any other county in New Mexico.
Sierra Grande, situated about 10 miles southeast of Folsom in Union County, is the largest single mountain in the United States. It is 40 miles around the base and covers 50 square miles, with an altitude of 8,720 feet. It is an dormant volcano. The Herzstein Memorial Museum in Clayton is one of the nation's finest small museums. The law was found to be unconstitutional, but after the hanging, unfortunately for Ketchum.