It’s a documentary that takes viewers across Northeast Wisconsin to the Niagara Escarpment. It is a ridge of rock millions of years old — reaching from east-central Wisconsin all the way to Upstate New York. UW-Green Bay Prof. John Luczaj (Geology) is one of many experts in the film telling the story of the natural rock ledge — filled with caves, waterfalls and rocks slopes formed over time, carved through erosian by rivers and glaciers, “People should know the aspects of the geology and biology that are relative to their region,” said Luczaj. “The Great Ledge” premieres Wednesday, April 26 at 6:30 p.m. at the De Pere Cinema. Tickets for the event, a fundraiser for that school curriculum project, are $10. WFRV-TV previewed the documentary.