Formed January 1, 1894 (18th county)
Union County (4,083), Clayton (2,657)
The classier Beaux Arts red brick courthouse is sited on a square at Court Street, 1st Avenue, Adams Street, and 2nd Avenue. The site is one block south of United States Highway 56. The facility was constructed in 1910 using the designs of D. P. Kaufman and Sons. The courthouse features a dome and columns. There was a previous courthouse built in 1895 in Clayton, the only county seat. The county was created on January 1, 1894 from Colfax County as the 18th county and later yielded land for Harding and Quay counties. Senator Stephen W. Dorsey’s son, Clayton, is the source for the county seat name. The county was named for the union of the states.
Union County government consists of a manager, a sheriff, a treasurer, an attorney, an assessor, and a clerk (executive). It has 3 Commissioners (legislative.) Two District Court Judges serve Union, Colfax, and Taos counties (judicial.) Union County is in the northeast corner of New Mexico sharing borders with Colorado, Oklahoma, and Texas. The Cimarron River and North Canadian River both cross the county from west to east. The county center is 17.2 miles West-Northwest of Clayton nearer Mount Dora. The county is surrounded clockwise by Colorado, Oklahoma, and Texas and Quay, Harding, and Colfax counties.
The area of the county is 3830 square miles. It is 15 out of 33 in the state. It ranks 30 out of 33 in population in the state. It has a density of 1.1 persons per square mile making it 30 out of 33 in the state. Union County has 69.7% of its population in its incorporated areas. United States Highway 56 crosses the county from Oklahoma, northeast, to Colfax County, west. United States Highway 64 is joined with United States Highway 56 from Oklahoma, splits in Clayton, and heads northwest into Colfax County. United States Highway 87 enters from the east (Texas), joins United States Highway 64, and exits northwest (Colfax County). United States Highway 412 is joined across the county with United States Highway 56. The county is shaped like a small letter q. Clayton is in the eastern quarter of the county. Clayton is the county seat and the largest city. It is 65.1% of the county population.
Clayton
Des Moines
Folsom
Grenville
