Quarryhill, I think is woefully understaffed (as am I!). They're located just down the mountain from me, so to speak, and I volunteered in 2016 to survey their Rosa collection. Bill McNamara gave me permission to collect herbarium specimens and take cuttings. Tags are the bane of collections. If you hang it on the bush it gets engulfed and lost as the plant grows (and anyone who's tried to retrieve a tag inside a thorny rosebush knows how fun that is). If you put it in the ground it's destroyed or lost during weed control. And then there's the short half-life of the tag itself. Quarryhill wants to GPS their entire collection. I have one of those handheld GPS devices and used it while making my survey. I do the same in my own garden. Unfortunately I developed physical mobility issues and after a spring of visits had to quit. I discovered and learned a lot, they have a wonderful collection and a seemingly inexhaustible source of water to make it all thrive. I wish gardens like theirs could get supported somehow, someway. It's the only safe refuge for these rare species.
Hope to post soon photos of the many species growing there and my notes on them.