Fellow member
Jo M posted about her beautiful River Trees quilt in 2013 at this link:
My version of River Trees.
She also used the 'fast 45' method details of which she says can be found with the free pattern and she provides a link. The link did not work for me so I'm guessing it is no longer valid. In that case, what about contacting
Jo M direct and asking her?
https://www.quiltingboard.com/members/jo-m-u16594.html