Questions about kidney disease? Call toll-free at 855.NKF.CARES (855.653.2273) or email nkfcares@kidney.org. The National Kidney Foundation of the Dakotas is an affiliate of the national organization. The NKF of South Dakota opened an office in Sioux Falls, S.D. in the year 2000. North Dakota was added in November 2004. Educating the public through public screening, patient and professional education is a high priority. The NKF of South Dakota is committed to increasing the availability of all organs for transplantation through its organ donation efforts.