Still being reviewed… They have thousands of trees planted, and have had at least three generations of trees in the “wild” (in very controlled plots). There has been a lot of fort going in to introducing more diversity into the Darling 58 variety, with pollen from a wide range of American Chestnut populations being used to make the next generation.

Here’s the 2021 update for the program: https://www.esf.edu/chestnut/progress-report/2021.htm