From Wikipedia, the free encyclopedia. National Wildlife Refuge is a designation for certain protected areas of the United States managed by the United States Fish and Wildlife Service. The National Wildlife Refuge System is the system of public lands and waters set aside to conserve America's fish, wildlife and plants.he National Wildlife Refuge System is dealing with such issues as urban intrusion/development, habitat fragmentation, degradation of water quantity and quality, climate change, invasive species, increasing demands for recreation, and increasing demands for energy development.