Most of the photos show life on the ranches - herding cattle and riding horses - but they also offer a glimpse of some of the small towns and the newly-built railway.
It is thought that the majority of the images were captured by a British person who travelled to America to work as a farmhand before returning with a whole album of photos.
The set emerged as it was put up for sale by the estate of a deceased collector of photographs from Surrey.
The pictures will go under the hammer at Flints Auctions on 21 June where they are expected to fetch £500.
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