Rio Rancho lies mostly in Sandoval County but a small portion crosses the line into Bernalillo County. As of 2010, Rio Rancho is the third-largest and the fastest growing city in New Mexico. The townsite was originally part of the Alameda Land Grant of 1710. As the land grant was settled and the papers were all in order, the owners of record in 1847 were able to hold onto title to the land but most of it had been sold to land speculators by the early 1900's.

Amrep Corporation bought some 55,000 acres in 1961 and surveyed, platted, registered, bulldozed roads and started selling that property as Rio Rancho Estates. Many of the first buyers were from New York and they started building and moving their families in by the mid 1960's. The population grew tenfold between 1970 and 1980. That led to the city's incorporation in 1981. Another impetus pushing incorporation was a deal with Intel Corporaiton to build a major semi-conductor plant in town: the folks of Rio Rancho wanted to have some amount of say as to what was going to happen with all the tax money involved.

In the 1990's, Rio Rancho took steps to differentiate itself from Albuquerque in order to become a real city in its own right. Among the first steps taken then were the establishment of separate library and school systems. Then came the establishment of a large industrial park and efforts to recruit new businesses to the area. The downtown area has also seen considerable development with a new city hall being opened for business in September 2007, a satellite University of New Mexico campus, a Central New Mexico Community College campus and the Santa Ana Star Center, a 7,000-seat event center/sports arena.