SnowEx 2017 was the first in a multi-year series of airborne remote sensing campaigns, designed to address gaps in snow retrieval techniques in preparation for a future snow satellite mission. This field campaign targeted the impact of increasing forest density on both snow remote sensing uncertainty and on snowpack processes. A variety of sensor types were flown to collect multi-sensor airborne data. In combination with detailed ground truth, this multi-sensor dataset enables critical trade studies to determine optimum sensor-plus-model combinations for different snow conditions and confounding factors. This field campaign was executed in Colorado, with intensive airborne remote sensing and ground-based observations in Grand Mesa and Senator Beck Basin. The Intense Observing Period (IOP) took place February 6-25th 2017 and included approximately 100 participants from across the international snow research community.