On the short list of great cartoonists in the 20th Century, J.N. "Ding" Darling also left one of the finest and most impressive legacies through his dedication to conservationist causes and protecting the natural world.
This Des Moines Register article seems to indicate that his foundation believes they've fulfilled their initial mission and are thus winding down through an offer of matching donations to various related causes, which seems to me a completely classy way to wrap things up. It looks like they also offer a CD-ROM of the artist's work.