Lake Ontario is 193 miles by 53 miles. Yet with its great average depth (approximately 283 feet), Lake Ontario holds almost four times the volume (395 cubic miles) as Lake Erie and has a retention time of about 6 years. The drainage basin covers parts of Ontario and New York, and a small portion of Pennsylvania. Major urban industrial centers, such as Hamilton and Toronto, are located on its shore. The U.S. shore is less urbanized and is not intensively farmed.