I proceeded to Google for more info, and all that was popping up was a Lancaster-Lebanon Quilt Show in April, which didn't look particularly Amish. I emailed the organizers and they very nicely got back to me and let me know that the heritage show ceased to exist in 1990.

Then, on amishquilter.com, I found reference to an "annual Quilters Heritage Celebration". Great! Maybe I'll attend this year.

First, I found the Amish subreddit, which perhaps not surprisingly has... no posts.