Particle tracking models can simulate the path of volcanic ash particles that might affect airplane flights, the path of contaminants from a pollution source in the atmosphere or in a water body, and the path of organisms through the either a water or air environment. These models can be used in hazard assessments, environmental planning and biological research. Model outputs include locations of particles in space and time and associated environmental measures such as temperature, wind or current speed and direction, water turbidity, and water salinity. The outputs may include both a fully populated four-dimensional grid of environmental attributes and the x, y, z, t location of the particle(s). A geographic information system (GIS) can provide tools to display and analyze the results of tracking models. In this paper we report on the development of a tool to display particle tracks in 3-D, to display and analyze the environmental variables along the track of one or more particles and to integrate particle tracks with a variety of spatially-explicit datasets. The tool uses functions native to ESRI's ArcGIS, Java-based statistical and analysis tools, functions from VTK, and display tools from Unidata's Integrated Data Viewer (IDV).