When does The Rifleman Happen?

According to Wikipedia: "It was set in the 1870s and 1880s in the fictional town of North Fork, New Mexico Territory."

I just saw part of the episode "The Indian" (17 February 1959) and it has a strong clue as to its date.

There are several Apache characters in the episode, including Eskiminzin, portrayed by Robert Chadwick. Robert Chadwick was born September 2, 1933 and died December 7, 1997 according to IMDB.

So Robert Chadwick was 25 years 5 months, and 15 days old when "The Indian" was broadcast, and probably a few weeks or months younger when his scenes were filmed.

Thus one might suppose that Eskiminzin should be about 25 years old in "The Indian", and since Eskiminzin is a real name in the Apache language and was the name of a real Apache, "The Indian" should happen about when the real Eskiminzin was about 25 year old. The Wikipedia article on Eskiminzin says that he lived 66 years from 1828 to 1894.

And so this line of reasoning suggests that the episode "The Indian" should happen about 1853, two or three decades before the era that Wikipedia suggests The Rifleman is set in!

Of course one might say that the creators of "The Indian" carelessly hired actor Robert Chadwick to portray Eskiminzin despite Chadwick being two or three decades too young and the episodes does happen in the 1870s or 1880s. But there is another problem with the portrayal of Eskiminzin in "The Indian".

The leader of a group of Apaches in the episode is Chief Hostay (Frank DeKova, 1910-1981), who is said to be Eskiminzin's father. I don't know if Hostay was a real person or who Eskiminzin's father was. But obviously if Eskiminzin's birth year of 1828 is close to being correct, his father would probably have been in his seventies or eighties in the 1870s and 1880s. That would have been unusually old for an Apache, even if a lot younger than Nana (1800?-1894) or Jason Betzinez (1860-1960) lived to be.

And Eskiminzin was not a ordinary ranking Apache in the 1870s and 1880s. By about 1870 Eskiminzin was a local group chief of the Aravaipa band of the Western Apaches. In the 1860s the western Apache tribes and bands were fighting a number of wars with the Americans. In 1871 the Apache bands of Eskiminzin and Captain Chiquito settled down in peace near Camp Grant.

Unfortunately William S. Oury, Jesus Maria Elias, and Chief Franciso Galerita, and their American, Mexican-American, and Tohono O'odham followers all believed that the only good Apache was a dead Apache, and massacred about 144 Apaches, mostly women and children, near Camp Grant in 1871. The massacre was one of the reasons why the US government sent envoys Vincent Colyer and General O.O. Howard to negotiate peace and establish reservations for the various western Apache bands and tribes, and General George Crook to crushingly defeat those Apaches who refused to make peace in 1872-73.

Though there were a number of Apache outbreaks until 1886, the vast majority of the western Apaches remained in peace on their reservations ever since 1872-73, and so for the rest of Eskiminzin's life.

So clearly Eskiminzin was not exactly the best historic name to choose for a young Apache warrior who was the son of a living chief in any episode that was set in the 1870s or 1880s, and thus indicates that The Rifleman happens more in the wild west of the imagination than in real history.

So what is the evidence in various episodes of The Rifleman that would give clues to the fictional dates of various episodes?