Located about 200 kilometers east of Toronto and 400 west of Montreal, the Bay of Quinte is a long, thin bay in the shape of a letter "Z". The northern side of the bay is defined by the mainland, while the southern side follows the shore of the Prince Edward County headland. Beginning in the east with the outlet to Lake Ontario, the bay runs west-southwest for 25 kilometers to Picton, where it turns north-northwest for another 20 kilometers as far as Deseronto. From there it turns south-southwest again for another 40 kilometers, running past Big Island on the south and Belleville on the north. The width of the bay rarely exceeds two kilometers. The bay ends at Quinte West (formerly Trenton) and the Trent River, both also on the north side. The Murray Canal has been cut through the few miles separating the end of the bay and Lake Ontario on the west side. The Trent River is part of the Trent-Severn Waterway, a canal connecting Lake Ontario to Lake Simcoe and then Georgian Bay on Lake Huron.
The Bay, as it is known locally, provides some of the best trophy Walleye angling in North America as well as most sport fish common to the great lakes. The Bay is subject to algae blooms in late summer which are a naturally occurring phenomenon and do not indicate pollution other than from agricultural runoff. Zebra mussels as well as the other invasive species found in the great lakes are present.
The Quinte area played a vital role to bootleggers during Prohibition in the US, with large volumes of booze being produced in the area, and shipped via boat on the Bay, to Lake Ontario finally arriving in New York State where it was distributed. Illegal sales of liquor accounted for many fortunes in and around Belleville, Ontario.