I read a book growing up and I have no idea what the name was but it was a fantasy novel about a girl traveling west during pioneer times.
Her wagon party stops (I think there was strife within the group) and she happens upon some other worldly battle (the word "realm"). She befriends some creature (who had an awesome name I can’t remember) and she gets a talisman that she buries at the crossroads of the town they settled in, that ended up being very successful.
I think a lot of it then takes place in modern-ish times? The book ends in some epic battle between aforementioned other dimensional characters.