The New York Times reports that Robert Ryman has donated the works on view at Dia:Beacon to the foundation:

Dia:Beacon, the Dia Art Foundation’s sprawling upstate outpost, has been an essential Ryman pilgrimage site since it opened in 2003, with rooms full of natural light dedicated to his mostly white, mostly square minimalist works. And now Mr. Ryman, 86, is cementing that status with a donation to the foundation’s permanent collection of the 21 works on view, which will remain on display along with another painting Dia already owns. Taken together, the paintings represent a sweep of Mr. Ryman’s career unparalleled in any other public collection and now virtually impossible, given prices for his work, to assemble on the market, where they might collectively reach into nine figures. […]

While institutions like the Museum of Modern Art, the Art Institute of Chicago and the Stedelijk Museum in Amsterdam have substantial holdings, the closing in 2014 of the Hallen für Neue Kunst, a contemporary museum in Schaffhausen, Switzerland, with the largest public display of Mr. Ryman’s painting, leaves Dia as the only remaining site with an extensive permanent grouping, featuring works made as early as the late 1950s and continuing up to 2003.

Robert Ryman, Minimalist Master, Donates Trove to Dia Art Foundation (The New York Times)