Abstract : This study utilized quantitative and morphology theory to describe the microstructure of cohesive granular materials and to relate microstructure to mechanical and physical properties. Snow was used as the experimental material. A unique feature of the theory developed in this grant involved the description of the necked areas which are the intergranular restricted regions which tie the grains together to form a bonded granular material. Using a set of criteria to specify what would constitute a neck, the formulation was developed to automatically identify the necks and determine their geometry as they appeared in surface sections. For the three-dimensional properties, the necks were modeled as double truncated cones in order to provide an accurate description of the neck geometry and volume. Stereology theory was then used to calculate the three dimensional properties of the necks based on this model. In addition, other features such as pore size, grain size, coordination number and density were found. The final computer code consisted of approximately 150,000 lines of code and represents a very effective and automated means of describing cohesive granular materials. Finally an elastic-viscoplastic constitutive relation utilizing microstructure of the material was developed and validated against experimental data. (MM)