A member of the Blackfoot tribe, Richard Boss Ribs is imbibing in a bar when the call of nature strikes. He heads for the nearest indoor urinal only to be greeted by a long line. Rather than gamble with his ability to control his authority over his bladder, Ricky decides to head outdoors. His intention to relieve himself is interrupted by an unexpected sight. An enormous elk is wreaking havoc on a number of the vehicles in the parking lot. The sight of this elk engaging in vandalism is somewhat ironic for Ricky. It was only very recently that Ricky had lost his privilege to hunt elk due to an unfortunate incident involving one dead pregnant elk and three of his friends.
Ricky is what his friends call him, but no one inside this bar happens to be his friend. It is a bar located just off the reservation. Instead of Native Americans, its patronage is overpopulated by white rednecks. These are not rednecks given to drunkenly accepting Ricky’s story that a big elk was responsible for all the damage to their pickup trucks. A chase ensues with Ricky at the lead being followed by several of the patrons. The next day the local newspaper will arrive with the headline: “INDIAN MAN KILLED IN DISPUTE OUTSIDE BAR” accompanying an article laying the blame for Ricky’s demise at the feet of some unidentified patrons. There are murmurs, however, that this presumption of guilt is misplaced.
The story then takes up a decade after Ricky’s mysterious death to focus on Lewis. Lewis is one of those friends who called a man named Richard by his nickname Ricky. Lewis has moved away from the reservation, just as Ricky had been planning to do before that ill-timed need to urinate in a bar with a long line for the bathroom. Lewis has also married a white woman named Peta and taken a job with the post office. One night, Lewis is in the midst of repairing a broken overhead lighting fixture when he is shaken to his core by the sight of an elk below. The vision so stuns him that he very nearly falls from the ladder only to be rescued from serious harm at the last minute by Peta. This will be just the first of several ghostly sightings of the elk and seeing it is what eventually drives Lewis to confess to his fellow Native American co-worker—the flirty Shaney—an ugly, hidden truth. This secret is the revelation of what actually happened the night of that incident which resulted in Ricky’s loss of hunting privileges.
The story Lewis tells Shaney is that he, Ricky, and their friends, Gabe and Cass, had chased a herd of elk into the elders’ section of the reservation. This area is well-known to be a place where it is forbidden to hunt. Nevertheless, hunting does take place resulting in several elk being killed, including the pregnant elk. The ugly part of the truth is that Lewis removed the fetus from the elk and buried it. Every other edible portion of the mother elk was later given to the elders, however. As they attempted to make their getaway, the game warden showed up.
In the wake of this confession, Lewis begins to suffer from paranoia that very quickly intensifies into something pathological. He begins to suspect Peta is actually the spirt of the dead elk coming for vengeance. It is only his ferocious desire for this not to be the case—combined with Shaney’s suddenly strange behavior—that result in his suspicion shifting away from Peta and toward Shaney. The paranoia reaches such an advanced state that this suspicion moves Lewis toward plotting to kill Shaney. The first attempt fails, but on the second attempt almost everything goes perfectly. The main thing keeping it from being a perfect murder is the evidence which now raises doubt that Shaney actually ever was the elk spirit at all.
Now Lewis has a dead—scalped—female co-worker whom Peta is already jealous of that must be disposed of before his wife comes back home. A noise coming from inside the house alerts him to the fact that it is already too late. He goes inside to find Peta on the ladder looking at the broken light. The sight of her husband’s hands covered in blood shocks her to the point that she falls and dies as the result of her head hitting brick.
So, Lewis is now one man with the bodies of two dead women that need to be disposed of as quickly as possible. That would be weird enough for anyone, but things suddenly get much weirder for Lewis. He suddenly realizes that Peta appears to be pregnant. History bizarrely repeats as he cuts open her womb just as he had with the mother elk. It is as this point that weird no longer suffices as Lewis finds a baby elk inside his wife’s womb. He grabs it and tries to flee but is killed by vigilante justice in pursuit.
The elk calf transforms into the Elk Head Woman who is reincarnated as a teenage girl. This girl eventually begins attending the same middle school as Gabe’s daughter, Denorah. Although Gabe’s biological offspring, he is prohibited by order of the court from having any contact with her. He cannot even attend her school basketball games. As for what is occupying Gabe’s time, he is busy arranging commemoration of Lewis’ death by trading one of his dad’s guns for payment on a sweat lodge with Cass.
It is in the sweat lodge that Gabe finds out from Cass for the first time that the elk they had killed was pregnant. Elk Head Woman has been busy killing dogs as well as a local cop named Victor. While all this is going on, things turn really dark between Cass and Gabe. There is a dispute over money which has the unexpected result of killing Jolene—the girlfriend of Cass—when a truck collapses on top of her. She had been inspecting the truck in a search for the money. In blind fury, Cass reaches for the gun and fires at Gabe but flinches at the last second as he pulls the trigger. This flick causes the bullet to merely graze Gabe’s ear on the way to its final destination inside Denorah.
The money turns out to have been hidden inside a thermos. Gabe uses that thermos to kill Cass. His plan to then kill himself with the gun dissolves in a weakening of his resolve. Instead of committing suicide, he goes to check on Denorah only to be shocked that the body is actually Nathan Yellow Tail—the son of Victor the cop. Both Gabe and Nathan then see the vision of the Elk Head Woman. This unexpectedly freakish occurrence causes Nathan to run blindly into a path of wild horses that trample over him. Gabe, his resolve strengthening once more, agrees to kill himself if Elk Head Woman will spare Denorah. When he finally does shoot himself, however, Elk Head Woman informs him that Denorah must die because she is his calf.
The next day, Denorah shows up at the sweat lodge and sees Elk Head Woman who is now fully confirmed to have been Shaney all along. She challenges Denorah to a basketball game of 21. During the game, Shaney injures herself which causes her to slowly transform into her true form as Elk Head Woman. Suddenly, Victor shows up and even Elk Head Woman is shocked by this resurrection. She insists against all evidence that she had killed him. This argument does nothing to stop Victor from shooting her. The effect of the gunshot fully completes the transition of Shaney into Elk Head Woman. Denorah follows Victor’s advice to run, but this simple command turns out to be much more difficult than it would seem. After Elk Head Woman kills Victor—again—she begins to chase after Denorah. This chase takes up the rest of the day. Denorah quite unexpectedly finds Nathan on horseback, apparently able to avoid death as mysteriously as his father. Denorah instructs Nathan to head into town while she continues leading Elk Head Woman in the opposite direction.
The final destination of the two women is precisely the spot where the elk massacre had occurred all those years ago. Denorah finally loses consciousness amid a field of bones while her pursuer digs up the buried remains of the calf. Except that what comes out of the grave is an elk calf that is very alive. At this point, a shot rings out and Denorah looks up to see that it is her stepfather—the game warden. He is readying himself to take one last kill shot, but she stops him. This merciful action allows Elk Head Woman to cast off the last remaining shred of her humanity and assume her true animal nature in full. She and the calf then disappear into the wilderness.