The copy of the book I'm reading is a hardcover that my son picked up at a "purging" sale at his school library. The cover looks like this:

However, the only image I could find while I was uploading this book to my Facebook page was this one:

I ask you, does that even look like the same book????! After laughing for a while, I asked myself what would lead to a pair of covers that are so different. My conclusion (which may or may not be complete hooey) is that somewhere along the line, someone decided to market the book to a different audience - women instead of men.
The first cover is, as I said, for the hardcover edition that was published in 1964. The second is from a paperback reissue (by a different publisher) in 1978. The first cover, I think, has masculine appeal - we have a group of men in buckskins, obviously engaged in some kind of frontier military action or hunting, since their guns are prominent in the picture. The second cover looks a lot like a romance novel cover (a tame one, since both the man and woman are fully clothed, ha ha, albeit in clothes that are NOT accurate for the historical period). I doubt a man browsing in a bookstore would pick up that book with a woman in a hot pink dress. I asked my husband if he would read it, and he gave me one of those looks, which I took as a "no." (LOL)
I'm guessing that somewhere along the way between 1964 and 1978, someone decided women would be a more lucrative market for this book than men. Although I'm not finished with the book yet, I don't see how on earth that decision was made. I think this is very much a book with a "male" orientation (not that I am saying there are books for men and different books for women - not at all!). Actually, the main character, Markham Cape, reminds me strongly of Alex Rider from the juvenile spy series my son liked so much a couple of years ago, or maybe even James Bond transplanted to the American frontier. There's something cool and detached about him, which I see as traits in a literary character that appeal more to men than to women. I know as a reader I like characters much better when I can identify with them (something that may or may not be influenced by the fact that I'm a woman).
Anyway, I'm really mystified by this woman on the cover. I'm nearly halfway through the book, and there hasn't yet been a woman in the story who has been anything more than a temporary flirtation for Mr. Cape. I bet if you put every line about a woman together, they wouldn't fill two pages. So now I expect a major plot turn of some kind...or is this a case of a cover that would "hook" the female reader and then deceive her???