What harbor is located at the mouth of the Genesee River on Lake Ontario?

Rochester Harbor is located at the mouth of the Genesee River on Lake Ontario. This harbor serves as an important access point for both commercial shipping and recreational boating. The Genesee River flows through Rochester, and its outlet into Lake Ontario creates the harbor, which has historically been significant for trade and transportation in the region.

Buffalo Harbor is situated at the eastern end of Lake Erie and does not connect to the Genesee River. Syracuse Harbor is located on Onondaga Lake and has no relation to the Genesee River. Oswego Harbor, while also on Lake Ontario, is found to the east of Rochester and is associated with the Oswego River. Each of these harbors has its own distinct geographical location and purpose, but Rochester Harbor uniquely connects to the Genesee River, solidifying its position as the correct answer in this context.