The Virginian S02E15 - The Invaders

Rancher Mike Tyrone (Ed Begley) purhases a ranch near Medicine Bow, and moves there with his daughter Margaret (Beverly Owen), and his two sons (Rees Vaughan and James McMullen). Tyrone tries to force surrounding ranchers to sell their spreads, eventually cutting off the water from a local river that the other ranchers use to water their stocks. However, the conflict is ended by an unexpected decision of Margaret Tyrone.