Woody plant invasion was investigated on Andrews and Gregory Balds in Great Smoky Mountains National Park. Both balds showed a steady, approximately linear decrease in area. Equations predict that Gregory Bald will be covered by forest about 2007 A.D. and Andrews Bald will be covered by 2042. Blueberries on Gregory Bald have increased from 20% cover in 1964 to 53% in 1975. Most of the regeneration on both grassy balds dates from the cessation of grazing. Hawthorn (Crataegus macrosperma) and serviceberry (Amelanchier laevis) are the most abundant invaders of Gregory Bald but red oaks (Quercus rubra) grow well, once they become established. Serviceberry is the most abundant species on the open portion of Andrews Bald, followed by fir (Abies fraseri) and hawthorn.