The GPM Cold Season Precipitation Experiment (GCPEx), a collaboration between NASA GPM ground validation (GV) program and its international partner, Environment Canada (EC), provided both new datasets and physical insights related to the snowfall process to ultimately improve falling-snow retrievals. The GCPEx field campaign occurred in Ontario, Canada, from 15 January to 3 March 2012. GCPEx collected microphysical properties, associated remote sensing observations, and coordinated model simulations of precipitating snow. The coordinated measurement strategy used stacked high-altitude GPM airborne remote sensing simulator instrumentation and in situ cloud aircraft flights with three research aircraft sampling within a broader network of five ground sites taking surface in situ and volumetric observations. Data collected during this field campaign exceeded all expectations, with measurements of heavy fluffy, non-melted, rate, moderate and light falling-snow rates, along with mixed-phase and rain cases. It is anticipated that the GCPEx dataset will satisfy the majority of GPM falling-snow retrieval algorithm validation objectives originally set forward for the experiment. These 3D datasets are suitable for conducting observational and modeling-based studies of bulk- and/or particle-scale snow microphysical and scattering properties observed at the ground, through the atmospheric column, and at high altitudes as observed from the vantage point of remote sensing instrumentation deployed on the GPM Core Observatory.