Later sessions returned to off-season dates, usually in January and February. The 1952 session inaugurated a field trip to observe museum practices in New York City institutions, to which a stop at Philadelphia was added the following year. The 1953 trainees were also encouraged to spend a weekend during the course at Colonial Williamsburg. Williamsburg would become the goal of a second field trip each year, but not until the course suffered an interruption. The death of Ned Burns in 1953 left the Museum Branch staff under too much pressure to continue preparing and conducting it, and it did not resume until January 1957. Annual sessions followed regularly for six more years, undergoing modification each time based on evaluations by trainees and staff. During this period class size averaged twelve to 15, usually with one or two from outside the Service, and the number of jobs in the curriculum increased to 21

The 1964 session presaged change. By that time the Stephen T. Mather Training Center at Harpers Ferry was in full operation. It offered a nineweek course in interpretation under experienced full-time instructors to classes of about thirty trainees whose expenses were paid out of programmed training funds. The Mather Center had a legitimate interest in the Museum Methods Course, for its content on museums and exhibits as interpretive tools appeared to overlap material in the Harpers Ferry course.14 The differences were subtle. The Museum Branch aimed its training at improving the use of museums in the parks, while the center addressed park interpretation as a whole with museums one of several presumably well-integrated media. As the first step in resolving the question of duplication, the Museum Branch and History Division conducted the 1964 session of their course at Harpers Ferry where the Mather Center staff could observe and appraise it.

The center concluded that it could absorb the museum content into its longer interpretation course, spelling an end to the History Division/ Museum Branch course. During its 13 sessions over a period of 15 years it had provided a modest measure of museum training to 131 Park Service employees. Many were field interpreters who later advanced to higher positions but continued to have some involvement in or influence over museum matters. Even so the course could not keep pace with the training needs of the growing number of staff members assigned to park museum duties. Unfortunately, it soon became evident also that the evolving Mather Center curriculum did not meet the need for training in curatorial techniques. With changes in center leadership, concern for collection care quickly disappeared as a substantive part of the basic interpretive methods course. A fresh effort to fill the gap would become necessary.