Blue Curls is known from many states and provinces in the eastern half of North America. It grows in coarse, acidic soils in open areas including prairies, savannas, open woodlands, sandhills, and pine flatwoods. Blue Curls relies on fire or other disturbance to persist as part of a local flora, as it is not tolerant of competition from other plant species.
Stable over its North American range, Blue Curls is also a species of concern in Indiana (State Rare). The site where we saw it in Michigan was excavated a few years ago, creating disturbed, open soil that is ideal. I have seen it at a few sites in Indiana, including one location in Porter County that historically was mined for sand and another along a recently excavated roadside berm in St. Joseph County (both, again, disturbed sandy soil). The yet to be answered question is: where does this species come from when there is no apparent seed source and sandy soil is excavated? Have the seeds been covered by years of sand and organic accumulation, just waiting for a disturbance to bring them back to the surface so that they can germinate? Are the seeds brought in by excavating equipment? My guess is the former, but then you have to wonder how long the seeds can remain viable. Surely, it takes hundreds, if not thousands, of years for a foot or more of soil to accumulate, meaning that the seeds may remain viable for that long. Nature is resilient.