On paper this movie looks like it might be following in the footsteps of Martin Scorsese’s Killers of Flower Moon, as another step forward in Hollywood’s representation of Native Americans. Directed by Jesse Edwards, it’s a contemporary western with a well-intentioned storyline about the economic exploitation of Indigenous people over generations, dispossessed of land and resources. The trouble is, it’s also quite possibly the most unconvincing film of the year, with characters so thin you can practically see through them, implausible plot twists and a couple of intensely cringey soap-opera moments.

Briza Covarrubias plays Lupe, a sweet and friendly mechanic in her 20s. Raised by her Navajo mum Adamina (Paula Miranda), Lupe has grown up believing that her father died before she was born. But when her mum is diagnosed with a brain tumour, there’s a shock revelation: he’s alive and owns the land Adamina grew up on. He might even be persuaded to stump up the $50,000 for her cancer treatment. Lupe sets off to find him.

But wait, before she even makes it on to the bus, Lupe walks into a shootout and goes on the run with a rodeo rider called Maddy (Allee Sutton Hethcoat, wearing what looks like a fancy dress cowgirl hat bought from Amazon). The script goes for some Thelma and Louise style scrapes as the two women dodge baddies, resulting in some stonkingly ridiculous moments, like the scene in a biker dive where Lupe dances flamenco with such passion she melts the hearts of the bar full of tattooed toughies.

The land where her mother grew up is Alta Valley (a fictional place, shot in Utah), now overrun by rednecks. The cinematography here, capturing the fierce beauty of the craggy landscape, raises the quality an inch or two above hokey cheapness. In the end though, this is movie with right on its side but not a scrap of believability.

• The Stolen Valley is on UK digital platforms from 15 April.