The IMPROVE Experiment had the goal of improving the microphysical parameterizations in mesoscale models by collecting comprehensive data in precipitating systems. IMPROVE took place in two phases during 2001. The first phase occurred along the Washington Coast and offshore waters and examining frontal/synoptic precipitating systems, while the second occurred over the Oregon Cascades and studied orographic precipitation. A central approach of IMPROVE was to collected both comprehensive basic state and microphysical data using a wide variety of platforms, including two aircraft (Convair 580, NOAA P3), the NCAR SPOL polarized radar, a vertically pointing S-Band radar, several 915 Mhz profilers, a water-vapor radiometer, additional radiosondes, and human ice crystal observers. This presentation will provide the context for the experiment, describe its observational assets, and provide some insights into initial findings.