They Call Me Renegade (1987) on Netflix

Plot summary

Luke roams the American Southwest in a Jeep with his chestnut colt, Joe Brown, paying his way with petty scams and living free of responsibility. His friend Moose is behind bars for a crime he says he did not commit, and has won an Arizona ranch in a poker game. Moose asks Luke to become Matt's legal guardian and to watch over the boy and the property until Matt turns eighteen. Neither Luke nor Matt warms to the arrangement, but the two set off for Arizona together. On the road, truckers in a semi try to drive them off it and a biker gang hassles them. At the rundown house by the lake, Amish neighbors welcome them, and visitors from Lawson Enterprises urge Luke to sell the land.