Hardy Ferns - http://www.hardyferns.org
This organization, based in western Washington state, works to "provide a comprehensive collection to the world's hardy ferns for display, testing, evaluation, public education and introduction to the gardening and horticultural community".
Rhody Garden - http://www.rhodygarden.org
A non-profit organization based in Federal Way, Washington is "dedicated to the conservation, research, acquistion, evaluation, cultivation, public display and distribution of Rhododendron species. Offers educational information on over 850 natural species. Great photos.