I spent my youth on the Navajo reservation and I totally echo jannert’s concerns. And skinwalkers are evil witches. Always. That’s how they got the power to shape shift.
I agree too. If you use the name skinwalker in your book, readers will assume it refers to Navajo's belief system, and you will come off as disrespectful if you don't follow strictly their definition. I would recommend changing the name of your creatures/powers to something else. If you are keen on showing a connection between the two then you can use a derivative like "skinrunner" (sorry it's ugly, but on the spot I couldn't come up with a better example), so that it is far enough from the original people won't feel you are misappropriating. And I do like the possibility to transform into different animals, maybe small and cute ones too! Well, unless it takes away from the story you want to tell. But I am biased, I like stories with animals.
because white people (dominating) have ravaged indigenous people on multiple levels throughout history.
I am sure it doesn't. But I recommend you think about it a bit longer, especially about how this may become an issue. At any rate, I think your story has a lot of potential, so looking forward to read it when you finish it.
I don't want to belabor the point about whether or not to include skinwalkers too much, but I do want to comment on this, There is a fundamental difference with vampires, werewolves, and demons that skinwalkers don't share. Mainly that becoming a skinwalker is always presented as a choice, which is not always the case with vampires, werewolves, and demons. It is the nature that a vampire and a werewolf can be turned against their will that gave rise to different interpretations. They become allegories to the strength of free will and ability to resist temptation. This is especially true in vampires, for werewolves there is also the element that as public opinion of wolves shifted so too did opinion on werewolves. Going from monsters that ravage livestock and kill people, to pack animals that eat to survive but are mostly just wilder versions of doggies. Now demons are slightly different in that they are evil by nature. Though because they are naturally evil it leads to a situation that should they choose to be good, they create an ultimate form of a redemption story, and again the power of free will. These are stories about the strength to rise above one's nature, which can be very meaningful. Now some origin stories have the fall of demons be a choice, but one that occurred long ago and spawned by feelings of pride and envy. This still lends credence to a possible redemption arc. With skinwalkers they choose to commit evil in order to gain power. This origin doesn't lend itself well to positive representation. And having a skinwalker who doesn't need to commit unforgivable acts in order to gain their power is just a shapeshifter. At which point the question is raised, why call them skinwalkers when they do not possess the defining characteristic of a skinwalker.
They might even turn into a polyester, which would really be scary.... I actually have quite high hopes for Adam's new story. I was fortunate to beta-read the one he just finished, and it was really good. Lots of personality in it, lots of innovative ideas and lots of chuckles, but also lots of tension and frightful stuff happening as well. It really kept me going. He's crossed over the line into an author I now trust to get it right.
but if you wanted to avoid cultural appropriation you could change the name of both the ranch and the 'skin walking' characters
It's a shame to let a good story go to waste for want of a little bit of re-naming. If you re-named those things, you could do anything you wanted, and nobody would see it as political at all.
If you're co-opting a mythology and not sticking to it, you're already making things up. So there's no real reason not to rename things.
I see what you want to do, but sometimes having good intentions is not enough to overcome politics. In this case, you need to be particularly careful on how you deal with the subject matter. If you think about it, Percy Jackson deals with Greek gods...However, if you feel so strongly about wanting to talk about skinwalkers, then have sensitivity readers read your work to make sure your novel comes across as you intend it.
Patricia Briggs has the Mercy Thompson series with a main character she classifies as a "walker" (native american shapeshifter). She is not a skinwalker who deals in death and she only has one form (coyote), which is an inherited trait. But, I believe she is regularly called a skinwalker. The idea being that the myths surrounding evilness, death, and witchcraft were lies in myths. The standard "call things evil that you don't understand".