This report presents and analyzes winter mobility data obtained during the winters of 1988 and 1989 at the Keweenaw Research Center, Houghton, Michigan. Traction data (1989) for the HMMWV, HEMTT, SUSV and M60 military vehicles, and the CRREL instrumented vehicle, are presented for hard-packed snow and for undisturbed snow overlaying ice. When these data are compared with an equation for undisturbed snow over soil or packed snow, slight reductions in traction are observed. Resistance data obtained in 1988 and in 1989 are evaluated based on a combined vehicle-snow parameter. An empirical equation based on this parameter and data form all the vehicles, including the CRREL instrumented vehicle using several different width tires, is developed. The resistance data and the empirical resistance equation are compared with the CRREL shallow snow mobility model (SSM2.0). The SSM2.0 predicted resistance is within 50% on average. The empirically derived resistance equation is slightly worse. The report recommends further research on vehicle motion resistance in snow., within 7% of the measured value. Motion resistance prediction remains unchanged in SSM2.0. This quantity is still not predicted with a desirable level of accuracy.