Harold Holmdhol, previously the director of the American School of Quito, Ecuador, assumed leadership at ASFG, bringing stability and a renewed sense of identity to the school after a period of turbulence. A significant transformation under Mr. Holmdohl's guidance was the relocation of the school to the present-day Colomos campus, marked by the groundbreaking ceremony on June 18, 1959, and the commencement of classes there in September 1960.

In 1965, ASFG achieved its first accreditation by the Southern Association of Colleges and Schools (SACS), and later gained recognition from the Department of Public Education of Jalisco and the University of Guadalajara. During the mid-70s, a deteriorating national economy and a severe peso devaluation in 1976 greatly impacted the school, heavily reliant on tuition for revenue. Mr. Holmdohl retired in 1977 after nearly two decades of dedicated service to the school.