An FBI agent with Sioux background (Kilmer) is sent to a reservation to help with a murder investigation, where he has to come to terms with his heritage. Slowly he rejects the intimidating tactics of his fellow FBI agents, who are not so interested in solving the crime as covering up an incriminating situation with the locals, and as he becomes more tuned to his heritage, the locals begin trusting him. Based on actual Reservation occurrences of the '70s
When a pro-government native American is shot dead on the Navajo reservation, the FBI sends Val Kilmer, a part-Sioux white enough to qualify for membership of the Ku Klux Klan, to accompany veteran hardnose Sam Shepard on the investigation, his presence being a sop to the anti-government activists heavily suspected of the killing.
Kilmer begins his detective work by beating up a hippie-haired Navajo biker (Greene) who turns out to be a reservation cop, but as he delves deeper into the predictable web of corruption that surrounds the case he gradually discovers his Native American roots, even having visions of ghost-dancing redskins (either ancestral memories of the Wounded Knee massacre or acid flashbacks to The Doors).
Despite an excellent cast - Kilmer cementing his position as a more-than-just-handsome leading man, Shepard in a sinister rerun of Gene Hackman's Mississippi Burning character, and Greene proving he has a career after Dances With Wolves - this, like the extremely similar The Dark Wind, is one of those films that tries to be a crass thriller and an examination of deeper issues, but is achingly obvious as the former while managing to be pompously annoying as the latter.
Splendid landscapes and interesting faces - the usual virtues of the Western - keep the film burbling along, even as the actual plot is falling apart.
A serious identity crisis doesn't help Thunderheart and in the end, it's hard to get worked up about a melange of uranium rights, mystic mumbo-jumbo and confused and confusing politics with only a funny old medicine man for light relief, however accomplished Kilmer and Shephard are.