Once belonging to the Lost River Ranch lease, the land that now comprises the Milk River Natural Area was grazed infrequently and was therefore deleted from the grazing lease under the Public Lands Act in 1978 and 1979. Some resource exploration has occurred over the years and several wells were drilled but have subsequently been abandoned. Coal was also briefly mined but due to the area's remoteness was also abandoned. The Milk River Natural Area and Kennedy Coulee Ecological Reserve were established with the intent "to protect and maintain the ecological and aesthetic character of a representative example of the Mixed Grassland Natural Region with minimal human interference;" specifically, protecting ecological diversity and processes, native species and habitats, rare and significant natural features, recreation, education, and scientific research. Management interference is intended to be minimal and "let nature take its course" wherever possible, while managing some ecological processes such as fires and controlled grazing. A balance of grazing regimes is important to maintain the combination of short and medium grasses defining the dry mixedgrass natural subregion. Cattle do not graze in the same way as the now-extirpated bison did, but have been used to simulate natural processes. Grazing management maintains the grassland ecosystem in its climax state, but overgrazing must be avoided to prevent soil erosion and loss of biodiversity. Rangeland health assessments aid this goal by periodically evaluating the area's ecosystem health, including measuring factors such as grazing intensity, weed occurrence, species composition, site stability, and soil and plant health. The 2011 rangeland survey concluded that the Milk River Natural Area overall is in excellent health and meeting its management goals, and that plant community health and grazing management were found to be far exceeding provincial standards.
