The Study of Precipitation, Lower Atmosphere and Surface for Hydrometeorology (SPLASH) is a study proposed by the National Oceanic and Atmospheric Administration (NOAA) to study environmental parameters connected to weather and water over mountainous terrain. As part of this effort, we will make measurements of atmospheric properties like temperature, winds, humidity, precipitation, clouds and turbulence as well as surface properties, like snow cover, soil moisture, snow reflectivity and more. Together, these observations are meant to inform the development and evaluation of modeling tools used by the National Weather Service and other entities to provide predictions over mountainous areas. The SPLASH campaign is envisioned to take place between fall 2021 and summer 2022.