That does seem to be a very nice and unusual find. I believe those small yellow "petals" are common on most (all?) ratibida columnifera, just rarely that big and never open all at once (that I've seen, anyway). More common to see them open as a ring that moves from bottom to top of the cone.... linked some photos below that show this.

Looks unique enough to work as named cultivar if someone could figure out how to legally tame it into a reliable performer. Thanks for sharing your find.

Here is a link that might be useful: Flower head of Mexican hat (Ratibida columnaris)

It would be interesting to see what Mr. Smarty Plants has to say about it at the Lady Bird Wildflower website. I'd be interested in seeds myself and would go back and gather some later on if you can remember where it was or mark the plant. It might be a new cultivar of the species.