What do you want a window treatment for: decoration, privacy, keeping out light/glare, etc.? All of the above, one of the above, or ??? Are there any other windows, or just that one?

More pictures of the room would probably be helpful, too.

Keeping out light is the main priority with decor being a close second. This is the only window in the room, and it’s what you see first as you enter—I’d love to find stylish curtains but am not sure where to place a curtain rod with the vaulted ceiling. It’s throwing me off!

Place it about 6" above the casing, as long you can have the curtain rod extend about 6" in each direction on either side of the window, to allow the curtains to "stack back". From the photo you posted, it looks like it could be possible.