Sanctuaries and zoos
Sanctuaries and Shelters
GreenPeople.org: view a list of most of the animal sanctuaries and wildlife reserves in the US and abroad, including elephant, bird, horse, and marine sanctuaries - most of these are "large" enough to host their own websites.
PetFinder.com: PetFinder.com: view a list of US animal welfare organizations by state - many of them smaller without their own websites
Global Federation of Animal Sanctuaries: formed in 2007 formed in 2007 by nationally and globally recognized leaders in the animal protection field for the sole purpose of strengthening and supporting the work of animal sanctuaries in the United States and abroad.
Zoos
Association of Zoos and Aquariums (AZA): Founded in 1924, the Association of Zoos and Aquariums (AZA) is a nonprofit 501c(3) organization dedicated to the advancement of zoos and aquariums in the areas of conservation, education, science, and recreation. Look for the AZA logo whenever you visit a zoo or aquarium as your assurance that you are supporting an institution dedicated to providing excellent care for animals, a great experience for you, and a better future for all living things.
World Association of Zoos and Aquariums (WAZA): WAZA's mission is to guide, encourage and support the zoos, aquariums, and like-minded organizations of the world in animal care and welfare, environmental education and global conservation.
List of Zoos: from Wikipedia.org, a list of zoos all over the world, with links to websites when available.