I was hiking and camping in Lost Maples near Vanderpool last week and was surprised to notice 2 mature madrones just a few feet off the trail amongst all the junipers, lacey oaks and red oaks... They were in the far west part of the park, the 'west loop'. A very pleasant surprise, since they were the first ones I'd seen other than in pictures. And at another place (don't remember where, but it was on the west side of the park), right on the side of the trail they have a small bushy sapling a few feet tall growing! I'm pretty sure it is one...
Anyway, just thought I'd mention it for people like me who aren't fortunate enough to have a ranch out in the hill country with these on it. Might be the only way to see one
Unfortunately I didn't find out about that nursery until now, so guess I'll have to go back soon!