Formed over 420 million years ago from the compressed sediments of a shallow, tropical sea and spanning nearly 1,000 miles in a wide arc across the northern Great Lakes, the Niagara Escarpment is one of the greatest geologic features of North America---virtually defining the northern shoreline of Lake Michigan-Huron. The steep cliff edge of a giant dolomitic-limestone cuesta, it often stands in sharp relief to the land around it, most prominently at Niagara Falls and throughout the Grand Traverse Islands, where limestone cliffs rise 100-200ft above the shores of Green Bay.
Ecologically, the Escarpment is so significant that its Canadian section was designated a UNESCO World Biosphere Reserve in 1990, placing it in the same league as the Galapagos, African Serengeti, and Florida Everglades. In Wisconsin alone, over 240 occurrences of rare plant and animal communities have been documented along the its length---including white cedars that are over 1,000 years old! Some of the unique plants and animals found along the Escarpment (such as glacial relict land snails) are found almost nowhere else on earth.
Despite this, no national park in the United States showcases the Niagara Escarpment to date. Not even the eponymous Niagara Falls, which is a National Heritage Area.