Geography of Kent and Dungeness have been formed by accumulation of alluvium. Kent's principal river, the River Medway, rises near Edenbridge and flows some 25 miles (40 km) eastwards to a point near Maidstone, when it turns north. Here it breaks through the North Downs at Rochester before joining the River Thames as its final tributary near Sheerness. The river is tidal as far as Allington lock, but in earlier times cargo-carrying vessels reached as far upstream as Tonbridge. The Medway has captured the head waters of other rivers such as the River Darent. There are other rivers in Kent, most notably the
Buffalo, Rochester and Pittsburgh Railway coal was the extension of the line north from Lincoln Park through Rochester up to the coal dock it built at the mouth of the Genesee River in 1896. With an initial capacity of 4,000 tons a day, it was expanded in 1909 and 1913. To get coal to Canada, the BR&P arranged a cross-lake ferry service with the Grand Trunk Railway. This service was highly successful, carrying passengers and coal cars to Cobourg and other lake destinations. By 1913, over a million tons of coal a year passed through the Rochester coal dock. As the national economy grew, more