Describe Vic Gregg's central struggle and motivation in Chapter 1 in simple terms. How does the metaphor of "obstructing a river" clarify both his internal state and the external pressures he faces?

From the book

ntered the hard head of Gregg, but today it seemed to him that the mountains found a solemn companionship in each other. ​ Out of the horizon, where the snowy forms glimmered in the blue, they marched in loose order down to the valley of the Asper, where some of them halted in place, huge cliffs, and others stumbled out into foothills, but the main range swerved to the east beside the valley, eastward out of his vision, though he knew that they went on to the town of Alder. Alder was Vic Gregg's Athens and Rome in one, its schoolhouse his Acropolis, and Captain Lorrimer's saloon his Forum.…

these evenings so bitterly that he purposely spent himself every day, so as to pass from supper into sleep at a stride. It needed a long day to burn out his strength thoroughly, so he set his rusted alarm-clock, and before dawn it brought him groaning out of the blankets to cook a hasty breakfast and go slowly up to the tunnel. In short, he wedded himself to his work; he stepped into a routine which took the place of thought, and the change in him was so gradual that he did not see the danger. A mirror might have shown it to him as he stood this morning at the door of his lean-to, for the…

t with breathless interest. Whatever it was that the strange fellow heard, a light had gleamed in his eyes for a moment. As he sauntered back towards the bed just a trace of it lingered about him, a hint of sternness. “Spring?” answered Gregg. “Yep, I smelled spring a few days back and I started out to find some action. ​ You can see for yourself that I found it, partner.” He stirred, uneasily, but it was necessary that the story should be told lest it reach the ears of this man from another source. It was one thing to shelter a fugitive from justice whose crime was unknown, perhaps trifling,…

. “You, boy; easy, damn you! Hello, Vic!” and he propped that restless hind foot on his inner thigh and extended a hand. “Go an workin', Dug, because I can't stop; I just want a rope to catch Grey Molly.” “You red devil—take that rope over there, Vic. You won't have no work catchin' Molly. Which she's plumb tame. Stand still, damn you. I never seen a Glencoe with any sense!—Where you goin', Vic? Up to the school?” And his sweaty grin followed Vic as the latter went out with the coil of rope over his shoulder. When Gregg reached the house, Nelly Pym hugged him, which is the privilege of fat…

t the Doane River had not sent a strong current licking over bank and tossed the whole village crashing down the ravine. One building was very much like other, but Gregg's familiar eye pierced through the roofs and ​ into Widow Sullivan's staggering shack, into Hezekiah Whittleby's hushed sitting-room, down to the moist, dark floor of the Captain's saloon into that amazing junkshop, the General Merchandise store; but first and last he looked to the little flag which gleamed and snapped above the schoolhouse, and it spelled “my country” to Vic. Mame consented to break into a neat-footed…