The area was first settled by Europeans around 1765, called by the Indian name "Ischua". Officially, this was illegal, as the British had declared the land in the Allegheny River watershed to be part of the Indian Reserve after conquering the territory in the French and Indian War two years prior. The surface is a hilly upland, separated into two distinct parts by the valley of the Allegheny. The highest points are above the valley. During the American Revolutionary War, the 1779 Sullivan Expedition established the first road to what would become Olean, blazing a trail to what is now Kittanning, Pennsylvania along the path of what is now New York State Route 16.