A possible concise summary is:
A US marshal from Santa Fe, Rusty Stevens, goes undercover to investigate a range war between the Rincon Land and Water Company and the Navajo tribe in Rincon. He befriends Amos Boling, the editor of the local newspaper, and Polly Medford, the daughter of a land agent who was killed by one of the company's men. He also pretends to be a hired gun for the company and learns that they are behind the fake Navajo raids and the forged lease that gives them access to the Indian reservation. He gets arrested for killing one of the company's men in self-defense, but escapes with the help of Polly and Chief Irahu, the Navajo leader. He then exposes the company's crimes and arrests its boss, Gorman, and his henchmen, who are revealed to be members of the Dalton gang. He also falls in love with Polly and decides to stay in Rincon to finish his job.
Here are the key facts extracted from the text:
1. A man was wounded by Indians and needs a doctor.
2. The wounded man was a US marshal from Santa Fe.
3. The marshal was saved by a stranger.
4. Chief Irahu is accused of murder and is at large.
5. The Rincon Land and Water Company is involved in disputes over land and water rights.
6. The Navajos are being blamed for raids they may not have committed.
7. A character named Rusty Stevens is involved in an investigation regarding the Navajos.
8. There's a conflict between the local newspaper and the sheriff's office.
9. The Dalton Gang is in town, working for the land company.
10. The land company wants the Indian reservation for cattle grazing due to water scarcity.
11. A lease held by the land company is a forgery.
These facts are based on the dialogue and events described in the provided text.