This case details the process of planning and carrying out archival research on municipal associations. Municipal associations are an understudied area of the political science and local government fields. This case study discusses the challenges and opportunities that arise from researching an understudied field, including the need to identify, locate, and collect primary data. The case study details the process of developing a Data Collecting Plan and executing a plan of archival research to conduct original, empirical analysis. By carrying out this process, I found and developed the data needed to carry out mixed-methods research and analyze the relationship between municipal associations’ memberships and their behavior in intergovernmental relations.