Keeseville is a village in both the Town of Au Sable in Clinton County, and in Chesterfield in Essex County. In 1815, an iron rolling mill here became the focal point for the formation of this industrial village. Iron mining and fabrication, lumbering and woodworking provided the primary economic-base for the town up through the mid-twentieth century. Many present-day residents commute to Plattsburgh. Over 30% of the population is of French ancestry, a reflection of historical settlement by French Canadians from the north.
Clintonville, in the western part of town, was one of the earliest settlements on the Ausable River. The Peru Steel Iron Company manufactured iron here and it is believed their iron forges supplied some of the first ironclad ships. Of particular note is the former hamlet of New Sweden, located along the Ausable River about two miles west of Clintonville. Destroyed by a flood, New Sweden was the site of iron forges, and logjams frequently backed up at its dam.
Ausable occupies the southeast corner of the County, bordered by Lake Champlain to the east and the Ausable River to the south. Settled about 1794, the town was formed from Peru in 1839. Iron ore was discovered in 1806 and settlements grew around this abundant and excellent quality resource.
Ausable is best known for the famous Ausable Chasm, a two-mile long, 200-foot deep gorge carved through 500 million year old Potsdam sandstone by the Ausable River. Roaring rapids, waterfalls and placid pools create spectacular views. Visitors worldwide have come to witness the grandeur and beauty of this natural attraction, privately owned and operated since 1870.