This study was initiated to secure quantitative data on growth characteristics of the major species in the mixed grass prairie of western North Dakota; to determine the extent and range in yearly variations in growth patterns of the species and of the type as a whole; to assess the general influence of climate as a cause for seasonal and yearly variations in growth patterns; and to interpret the data obtained in terms of their possible application to the practical grazing management of these grasslands. / This project was supported by the North Dakota Agricultural Experiment Station as a part of project Hatch 9-5: "Native range plants -- their growth and development in relation to the establishment of standards for their proper utilization."