This paper provides new insight into the evolution of geographical information science and systems (GIS) research via a computational analysis (in R) of 120,000 bibliographic records (from 1970 to 2022) downloaded from Scopus. We conduct an exploratory analysis of the data, then attempt to discover the thematic/topical structure of the GIS literature using the Structural Topic Model (STM) framework. We show how topics in GIS have evolved and discuss how our findings contribute to the understanding of the evolution and trajectory of GIS research. We conclude by highlighting the limitations of the approach and explaining our future research plans.