The area of Quebec, draining into James Bay, Hudson Bay and Hudson Strait, is even larger than the St. Lawrence watershed. It covers approximately 350,000 square miles. There are ten rivers on that watershed that exceed 200 miles in length and the largest lakes of the Province are at the headwaters of those rivers. The Fort George River and Koksoak River are more than 500 miles long; Lake Mistassini, 1,243 feet in elevation has an area of 840 square miles. Their economic use is very limited, except as hydroplane bases in summertime. Some are free of ice only from the end of June to the end of September. In Western Quebec, at the head waters of the Harricanaw and Nottaway Rivers, settlement is progressing in the mining district and the Clay Belt.
The drainage pattern of Quebec is still in a stage of youth, following the interruptions of the glacial period. There are thousands of lakes, ponds and swamps; waterfalls and rapids are common along most of the stream courses. The flow of these rivers is naturally very irregular; winter freezing, spring breakup and summer drought cause the rate of discharge to vary enormously. Navigation is possible only on the St. Lawrence and on a few short stretches of its tributaries; but water power is abundant, logging may be organized with proper devices, and the canoe offered a good means of transportation until the advent of the hydroplane.