Nothing can impress one with the heroism of this march like a visit to these low lands which are now proving of great value to horse and cattle owners of northern Illinois as grazing grounds. Though my journey over Clark's route was made at the driest and most favorable season of the year, the mists, heavy as clouds, lay along the Bonpas, Fox, Little Wabash, Big Muddy, and Skillet and between them, and a thunderstorm made the modern road a veritable slough. From Vincennes to Xenia, the Baltimore and Ohio Southwestern Railway is parallel with the old St. Louis Trace which was Clark's route here.[42] But the student will find the journey by the old trace, throwing its curling lengths along the hills from Lawrenceville to Sumner, a most interesting though taxing experience. At Sumner the trace drops into the bottom-lands where the mists seem to lie forever and where little villages are perched upon knolls of a few thousand feet in diameter, surrounded by swamps and prairies that are now being drained and cultivated widely. Here the old trace--for the ancient name clings to it--is helped along by dint of corduroy bridges and stone and wooden culverts. Between Sumner and Olney the corduroy bridges are frequent and exceedingly rough, particularly if you are hurrying along at nightfall to gain the portals of a comparatively comfortable inn at Olney. Westward the road ploughs its way through the marshes and the mist to the little Big Muddy and across to the Little Wabash about where the old trace ran. Here the fogs lie heaviest, shutting off all view of the low-lying, bushy wastes. In midsummer the fog and marshes warn the explorer away; what of this land when the rivers are loosed by the winter floods and are streaming wildly along the vast stretch of the stunted bush and vine? The scene presented to Clark's Virginians and Frenchmen in February 1779 cannot by any means be pictured by one to whom these swamps are unknown; to such as know them, the picture, though probably imperfect, is one of horror. To row a boat where the current is swift is fatiguing labor, and to walk in the water, when each step may find one in a sink-hole and where the rank grasses, growing from heavy tufts, hold one's feet as a cord, is all that the strongest man can endure for even a short period. The little spots of ground which here and there rise above the flood are covered with driftwood and infested with snakes.