As an object moves through space, it creates a track (or path) representing the object's past and present position and associated attributes. If data capture fails, then positions along the tracks are unknown. The particular problem we address in this paper is to create tracks of moving objects with missing data. We implement and test two techniques that create continuous tracks of two primate species (Ateles geoffroyi, the red spider monkey, and Cebus capucinus, the white-faced capuchin). Continuous tracks were needed to calculate home range and to analyze daily ranging patterns for each species. Establishing continuous tracks of primates through field data alone, however, was impossible due to challenging field conditions. The results of the analysis using tracks with interpolated positions helped establish that Ateles tend to move directly to their destination while Cebus tended to follow a more wandering track.