Continuously in print since 1983, Dictionary of New Mexico and Southern Colorado Spanish, has become a classic Spanish reference book, widely used in classrooms across the United States. As a teenager in Albuquerque, esteemed linguist and folkorist Rubén Cobos (1911-2010) was intrigued by and began documenting the regional variations of spoken Spanish. This was to become his work of a lifetime spanning seventy-five years. Dr. Cobos began recording Indo-Hispanic folklore material in the early 1940s. With the co-operation of the villagers, farmers, sheepherders, and other hard-working people in the small towns throughout New Mexico and Southern Colorado he recorded the nuances, slang and the regionally distinctive words of Spanish spoken in the communities of the upper Rio Grande and Southern Colorado.

Ruben Cobos spent a decade working on the revised and expanded edition of the dictionary, published in 2003. The Dictionary of New Mexico and Southern Colorado Spanish has assumed its place as the most authoritative reference on the archaic dialect of Spanish spoken in this region.