When the broad and shallow and rock-strewn river Susquehanna, on its way down from Otsego Lake in New York to the Chesapeake, breaks through the North Mountain, its valley expands to three or four miles in width, making a fertile region between the high enclosing ridges which the Indians called Maughwauwama, or the "extensive flat plains." This sonorous name underwent many changes, finally becoming known as Wyoming. Luzerne County is the lower and Lackawanna County the upper portion of this noted valley, which is the greatest anthracite coal-field in the world. These Wyoming coal measures underlie seventy-seven square miles, having veins averaging eighty feet in thickness, and about eighty thousand tons to the acre, the aggregate deposit of coal being estimated to exceed two thousand millions of tons. The large population and enormous production have caused all the railways to send in branches to tap its lucrative traffic, so that it is the best-served region in Pennsylvania. It has two large cities--Wilkesbarre, in Luzerne, and Scranton, in Lackawanna. Wilkesbarre is on the eastern Susquehanna river bank, a town of forty thousand people, named after the two English champions of American Colonial rights. It covers much surface in the centre of the valley, with suburbs spreading far up the mountain sides. But from almost every point of view in the city the outlook is over black culm-heaps or coal-breakers or at rows of coal cars, so that there is a monotony in the steady reminder of the source of their riches, the omnipresent anthracite. About twelve miles northwest of Wilkesbarre, up in the North Mountain range, is the largest lake in Pennsylvania--Harvey's Lake--elevated nearly thirteen hundred feet and covering about two square miles. It is named after one of the early pioneers from Connecticut, and its outflow comes down to the Susquehanna near Nanticoke Gap. Its pleasant shores are a favorite resort of the Wilkesbarre people. The flourishing city of Scranton is about nineteen miles north of Wilkesbarre, in the Lackawanna Valley. It has grown to a population of a hundred thousand people, and is picturesquely situated among the coal mines, with a higher elevation than Wilkesbarre, being nearly eleven hundred feet above tide, at the confluence of the Roaring Brook with the Lackawanna River; and it has extensive iron industries, being the chief city of northeastern Pennsylvania. The Wyoming and Lackawanna coal pits, while the greatest anthracite producers, are not generally so deep as those of the Lehigh or Schuylkill regions. The deepest Pennsylvania shaft goes down seventeen hundred feet near Pottsville. Some of the Wyoming galleries run a mile and a half underground from the shaft, following the coal veins underneath and far beyond the Susquehanna.