Blanco is a census-designated place in San Juan County, New Mexico, United States. Its population was 388 as of the 2010 census. Blanco has a post office with ZIP code 87412, which opened on March 6, 1901. U.S. Route 64 passes through the community. A parish was established in Blanco in 1900 with St. Rose of Lima Catholic Church being the mother church for many missions.