Never even heard about the Reformed Church in America. That’s how irrelevant they’ve become.
Most of these mainline Churches have been losing membership. I believe they are Dutch Reformed and traditionally extreme Protestant Calvinist like Presbyterian and Congregationalist. Mostly in Dutch areas like NY, NJ, and MI. Would not be many in say the south.
There's a lot about the states that were the original colonies that later-settled areas of America don't know about. Dutch pilgrims settled New York city and state in the early 1600s and brought Reform traditions with them. They probably don't know a lot about Tex-Mex culture, either.