To prevent fraternization between officers and enlisted men, separate quarters were standard for U.S. Army soldiers. At Castolon, in addition to the barracks, separate houses were built to house the commissioned officers and non-commissioned officers. These houses were barely used by the cavalry officers before the Mexican Revolution ended and they were assigned elsewhere. Originally, these houses had porches on each end of the building. However, after Wayne Cartledge purchased them in 1925, he modified the building by enclosing one side on each house to create kitchens for the residents.

Over the years these houses have been occupied by the Cartledge family, La Harmonia Company employees, visiting researchers, and national park staff. One of the houses operates as a ranger station and a temporary Visitor Center. The original Visitor Center was destroyed on May 22, 2019 when a fire in Mexico jumped the Rio Grande. Please respect the privacy of residents in these buildings.