Greg, I will go to this and see if I can find more info/shots to share with you.
It is a special event at Tagawa Gardens in Centennial Colorado this Saturday.
I took the picture out as it is from their website.
It is a seminar on "Bringing the Rocky's Home - Rock Gardens and Alpine Plants
And had a great picture of a hypertufa container with slates and rocks.
sent it as a treemail shared it with Lynn too