Ghost Dancing (1983)

Farm widow Sarah Bowman has been impoverished by the siphoning of her water supply. A nearby big-city aqueduct has priority over water rights, leaving the rural outskirts virtually dry. Attempting to bring her cause to the forefront, Sarah dynamites the reservoir, half-hoping that she'll be "martyred" in the process. When she fails to arouse public support, she targets the local power plant for her next blast. Assistant DA Anne Greyfeather, who as an orphaned Indian girl was virtually raised by Sarah, decides to challenge the water-department bureaucracy on McGuire's behalf.