This environmental assessment documents the Service's evaluation of refuge expansion activities to protect important bald eagle habitat at Karl E. Mundt National Wildlife Refuge. This refuge in southeastern South Dakota was one of the first national wildlife refuges established to protect bald eagles. The Jonas tract expansion will ensure that critical riverfront habitat, located between two existing units of the refuge, remains protected from the increasing pressures of development and subdivision.
Karl E. Mundt National Wildlife Refuge is located below the Fort Randall Dam within a 39-mile reach of the Missouri National Recreational River. Located in Gregory County, the refuge is part of the Lake Andes National Wildlife Refuge Complex. Refuge habitats are a mix of cottonwood and willow riparian woodlands along the Missouri River, native mixed-grass uplands, and woody draws descending from bluffs down to the river. The mature cottonwood trees along the river are highly sought after by wintering bald eagles as perching and roosting sites. A 1967 winter survey of the refuge area counted 283 bald eagles, which was believed to be the largest concentration of wintering eagles in the lower 48 states at that time. Currently, 50–300 eagles winter in this area, depending on the severity of weather conditions.
Bald eagles are highly susceptible to disturbance, especially during the winter on communal roosts. Subdivision can lead to subsequent development and increased year-round human activity. This would most likely alter the habitat integrity and attractiveness of this area to bald eagles, as well as undermine the values and benefits of the existing refuge to wildlife.
The purpose of the Jonas tract expansion of the refuge, as a conservation easement, is to protect one of the largest and most important winter roost areas for bald eagles in the lower 48 states, and valuable nesting area for bald eagles in the spring. Details about the Jonas tract expansion follow:
Environmental assessment 2005 (2 MB PDF)