The ability to predict the state of the ground is essential to vehicle mobility, both manned and unmanned, personnel movement as well as determining sensor performance for military and civilian activities. Being able to predict how and when surface conditions will hinder operations can result in large savings both fiscally and in efficiency. Weather impacted terrain conditions resulting in a high degree of clutter or negligible differences between the target and background can degrade sensor performance. The capability to deliver cargo and equipment to remote locations requires landing on semi-improved or austere airfields. The selected area must have sufficient soil strength to support the weight of airlift aircraft. Route planning can be optimized knowing surface conditions and the moisture/ice dependent soil strength. Both soil temperature and soil strength are in part dependent on soil moisture. Since it is not possible to extract sufficient soil moisture information from satellite data, either in situ measurements or state-of-the-ground models are required. In remote locations not controlled by friendly forces, in situ measurements are highly unlikely. The 1-D dynamic, all-season state of the ground model FASST (Fast All-season Soil STrength) was developed as part of the Army's Battlespace Terrain Reasoning and Awareness research program. The fundamental operations of FASST are the calculation of an energy and mass budget that quantify the flow of heat and moisture within the snow, soil and vegetation and their exchange at all interfaces (vegetation-air; vegetation-ground; vegetation-snow; ground-air; ground-snow; snow-air) using both meteorological and terrain data. Incorporated into the model are a three layer canopy and a one layer lower vegetation algorithm. FASST can also model bridges and underground voids. Terrain materials, including asphalt, concrete, bedrock, permanent snow, air and 18 engineering soil types are accommodated. FASST has been incorporated into the Air Force Weather Agency's (AFWA) Land Information System (LIS), a joint project with NASA-Goddard, to facilitate the distribution of model outputs to soldiers in the field. FASST also has been incorporated in other military target acquisition and mobility route planning programs. It has transitioned from the research arena to operations in a very short time.