Since about 1964, the Navajo Area Agency of the Bureau of Indian Affairs has been using the Fries/Rojas American English Series (New York: D. C. Heath, 1952-57) for all of the elementary schools throughout the Navajo reservation. Unfortunately, many of the excellent classroom teachers in the Navajo Agency schools are untrained in ESL methodology. Many of the teachers throughout the five sub-agencies of the Navajo area expressed a strong desire for a series of testing instruments, specifically designed for the Fries/Rojas materials, to evaluate the children's progress as they proceed through the materials. In June, 1967, the Navajo Area Agency2 contracted with us to develop a series of achievement tests3 specifically designed to evaluate the Navajo children's progress in the Fries/Rojas materials. This paper is a final report of the activities which occurred throughout the year 1967-68.