Gentianopsis crinita. This species is state-listed as "Potentially Threatened." As of 2008, this species has been recorded in only 10 counties here in Ohio, mostly in the north and northeast.
Ohio's Wildflowers and Flora. Andrew Gibson, a field botanist for ODNR and the blogger who runs the amazing Natural Treasures of Ohio, IDed it as a Greater Fringed Gentian. He said "there is distinct fringing across the summit of the petals and the cauline leaves are more lance-ovate and stubby. Lesser Fringed Gentian's leaves are much narrower/linear and longer by comparison."
Both of these flowers were a completely unexpected find; I'm very happy we stopped by the park! I've been going on these weekend salamander research trips for the last 3 weeks, and I've seen a lot of cool stuff. I'll be working on a few more blog posts that go over some of the things I've been able to get photos of, so stay tuned!